default search action
Grey Ballard
Person information
Refine list
refinements active!
zoomed in on ?? of ?? records
view refined list in
export refined list as
2020 – today
- 2024
- [j25]Hussam Al Daas, Grey Ballard, Laura Grigori, Suraj Kumar, Kathryn Rouse:
Communication Lower Bounds and Optimal Algorithms for Multiple Tensor-Times-Matrix Computation. SIAM J. Matrix Anal. Appl. 45(1): 450-477 (2024) - [j24]Rachel Minster, Zitong Li, Grey Ballard:
Parallel Randomized Tucker Decomposition Algorithms. SIAM J. Sci. Comput. 46(2): 1186- (2024) - [c38]Cade Wiley, Grey Ballard:
Visualizing PRAM Algorithm for Mergesort. IPDPS (Workshops) 2024: 365-368 - [c37]Aditya Devarakonda, Grey Ballard:
Sequential and Shared-Memory Parallel Algorithms for Partitioned Local Depths. PP 2024: 53-64 - [i35]Koby Hayashi, Sinan G. Aksoy, Grey Ballard, Haesun Park:
Randomized Algorithms for Symmetric Nonnegative Matrix Factorization. CoRR abs/2402.08134 (2024) - [i34]Hussam Al Daas, Grey Ballard, Laura Grigori, Suraj Kumar, Kathryn Rouse, Mathieu Verite:
Communication Lower Bounds and Optimal Algorithms for Symmetric Matrix Computations. CoRR abs/2409.11304 (2024) - 2023
- [j23]Rachel Minster, Irina Viviano, Xiaotian Liu, Grey Ballard:
CP decomposition for tensors via alternating least squares with QR decomposition. Numer. Linear Algebra Appl. 30(6) (2023) - [j22]Hussam Al Daas, Grey Ballard, Paul Cazeaux, Eric Hallman, Agnieszka Miedlar, Mirjeta Pasha, Tim W. Reid, Arvind K. Saibaba:
Randomized Algorithms for Rounding in the Tensor-Train Format. SIAM J. Sci. Comput. 45(1): 74- (2023) - [c36]Srinivas Eswar, Benjamin Cobb, Koby Hayashi, Ramakrishnan Kannan, Grey Ballard, Richard W. Vuduc, Haesun Park:
Distributed-Memory Parallel JointNMF. ICS 2023: 301-312 - [c35]Hussam Al Daas, Grey Ballard, Laura Grigori, Suraj Kumar, Kathryn Rouse:
Parallel Memory-Independent Communication Bounds for SYRK. SPAA 2023: 391-401 - [d2]Srinivas Eswar, Benjamin Cobb, Koby Hayashi, Ramakrishnan Kannan, Grey Ballard, Rich Vuduc, Haesun Park:
AminerMag S Dataset. Zenodo, 2023 - [d1]Srinivas Eswar, Benjamin Cobb, Koby Hayashi, Ramakrishnan Kannan, Grey Ballard, Rich Vuduc, Haesun Park:
AminerMag X Dataset. Zenodo, 2023 - [i33]Aditya Devarakonda, Grey Ballard:
Sequential and Shared-Memory Parallel Algorithms for Partitioned Local Depths. CoRR abs/2307.16652 (2023) - 2022
- [j21]Hussam Al Daas, Grey Ballard, Peter Benner:
Parallel Algorithms for Tensor Train Arithmetic. SIAM J. Sci. Comput. 44(1): 25- (2022) - [c34]Hussam Al Daas, Grey Ballard, Lawton Manning:
Parallel Tensor Train Rounding using Gram SVD. IPDPS 2022: 930-940 - [c33]Hussam Al Daas, Grey Ballard, Laura Grigori, Suraj Kumar, Kathryn Rouse:
Brief Announcement: Tight Memory-Independent Parallel Matrix Multiplication Communication Lower Bounds. SPAA 2022: 445-448 - [i32]Hussam Al Daas, Grey Ballard, Laura Grigori, Suraj Kumar, Kathryn Rouse:
Tight Memory-Independent Parallel Matrix Multiplication Communication Lower Bounds. CoRR abs/2205.13407 (2022) - [i31]Hussam Al Daas, Grey Ballard, Laura Grigori, Suraj Kumar, Kathryn Rouse:
Communication Lower Bounds and Optimal Algorithms for Multiple Tensor-Times-Matrix Computation. CoRR abs/2207.10437 (2022) - [i30]Rachel Minster, Zitong Li, Grey Ballard:
Parallel Randomized Tucker Decomposition Algorithms. CoRR abs/2211.13028 (2022) - 2021
- [j20]Srinivas Eswar, Koby Hayashi, Grey Ballard, Ramakrishnan Kannan, Michael A. Matheson, Haesun Park:
PLANC: Parallel Low-rank Approximation with Nonnegativity Constraints. ACM Trans. Math. Softw. 47(3): 20:1-20:37 (2021) - [c32]Grey Ballard, Sarah Parsons:
Visualizing Parallel Dynamic Programming using the Thread Safe Graphics Library. EduHPC@SC 2021: 24-31 - [c31]Zitong Li, Qiming Fang, Grey Ballard:
Parallel Tucker Decomposition with Numerically Accurate SVD. ICPP 2021: 49:1-49:11 - [c30]Grey Ballard, Jack Weissenberger, Luoping Zhang:
Accelerating Neural Network Training using Arbitrary Precision Approximating Matrix Multiplication Algorithms. ICPP Workshops 2021: 16:1-16:8 - [i29]Hussam Al Daas, Grey Ballard, Paul Cazeaux, Eric Hallman, Agnieszka Miedlar, Mirjeta Pasha, Tim W. Reid, Arvind K. Saibaba:
Randomized algorithms for rounding in the Tensor-Train format. CoRR abs/2110.04393 (2021) - [i28]Rachel Minster, Irina Viviano, Xiaotian Liu, Grey Ballard:
CP Decomposition for Tensors via Alternating Least Squares with QR Decomposition. CoRR abs/2112.10855 (2021) - 2020
- [j19]Grey Ballard, Alicia M. Klinvex, Tamara G. Kolda:
TuckerMPI: A Parallel C++/MPI Software Package for Large-scale Data Compression via the Tucker Tensor Decomposition. ACM Trans. Math. Softw. 46(2): 13:1-13:31 (2020) - [c29]Lawton Manning, Grey Ballard, Ramakrishnan Kannan, Haesun Park:
Parallel Hierarchical Clustering using Rank-Two Nonnegative Matrix Factorization. HiPC 2020: 141-150 - [c28]Grey Ballard, Kathryn Rouse:
General Memory-Independent Lower Bound for MTTKRP. PP 2020: 1-11 - [c27]Srinivas Eswar, Koby Hayashi, Grey Ballard, Ramakrishnan Kannan, Richard W. Vuduc, Haesun Park:
Distributed-memory parallel symmetric nonnegative matrix factorization. SC 2020: 74 - [i27]Hussam Al Daas, Grey Ballard, Peter Benner:
Parallel Algorithms for Tensor Train Arithmetic. CoRR abs/2011.06532 (2020)
2010 – 2019
- 2019
- [j18]Fatemeh Mokhtari, Paul J. Laurienti, Walter Jack Rejeski, Grey Ballard:
Dynamic Functional Magnetic Resonance Imaging Connectivity Tensor Decomposition: A New Approach to Analyze and Interpret Dynamic Brain Connectivity. Brain Connect. 9(1): 95-112 (2019) - [i26]Grey Ballard, Alicia M. Klinvex, Tamara G. Kolda:
TuckerMPI: A Parallel C++/MPI Software Package for Large-scale Data Compression via the Tucker Tensor Decomposition. CoRR abs/1901.06043 (2019) - [i25]Chao Wang, Grey Ballard, Robert J. Plemmons, Sudhakar Prasad:
Joint 3D Localization and Classification of Space Debris using a Multispectral Rotating Point Spread Function. CoRR abs/1906.04749 (2019) - [i24]Srinivas Eswar, Koby Hayashi, Grey Ballard, Ramakrishnan Kannan, Michael A. Matheson, Haesun Park:
PLANC: Parallel Low Rank Approximation with Non-negativity Constraints. CoRR abs/1909.01149 (2019) - [i23]Grey Ballard, James Demmel, Ioana Dumitriu, Alexander Rusciano:
A Generalized Randomized Rank-Revealing Factorization. CoRR abs/1909.06524 (2019) - 2018
- [j17]Casey Battaglino, Grey Ballard, Tamara G. Kolda:
A Practical Randomized CP Tensor Decomposition. SIAM J. Matrix Anal. Appl. 39(2): 876-901 (2018) - [j16]Ramakrishnan Kannan, Grey Ballard, Haesun Park:
MPI-FAUN: An MPI-Based Framework for Alternating-Updating Nonnegative Matrix Factorization. IEEE Trans. Knowl. Data Eng. 30(3): 544-558 (2018) - [c26]Grey Ballard, Koby Hayashi, Ramakrishnan Kannan:
Parallel Nonnegative CP Decomposition of Dense Tensors. HiPC 2018: 22-31 - [c25]Oguz Kaya, Ramakrishnan Kannan, Grey Ballard:
Partitioning and Communication Strategies for Sparse Non-negative Matrix Factorization. ICPP 2018: 90:1-90:10 - [c24]Grey Ballard, Nicholas Knight, Kathryn Rouse:
Communication Lower Bounds for Matricized Tensor Times Khatri-Rao Product. IPDPS 2018: 557-567 - [c23]Koby Hayashi, Grey Ballard, Yujie Jiang, Michael J. Tobia:
Shared-memory parallelization of MTTKRP for dense tensors. PPoPP 2018: 393-394 - [c22]Grey Ballard, James Demmel, Laura Grigori, Mathias Jacquelin, Nicholas Knight:
A 3D Parallel Algorithm for QR Decomposition. SPAA 2018: 55-65 - [i22]Grey Ballard, Christian Ikenmeyer, J. M. Landsberg, Nick Ryder:
The geometry of rank decompositions of matrix multiplication II: 3×3 matrices. CoRR abs/1801.00843 (2018) - [i21]Grey Ballard, James Demmel, Laura Grigori, Mathias Jacquelin, Nicholas Knight:
A 3D Parallel Algorithm for QR Decomposition. CoRR abs/1805.05278 (2018) - [i20]Grey Ballard, Koby Hayashi, Ramakrishnan Kannan:
Parallel Nonnegative CP Decomposition of Dense Tensors. CoRR abs/1806.07985 (2018) - 2017
- [j15]Grey Ballard, Mary W. Hall, Tim Harris, Brandon Lucia:
Guest Editor Introduction PPoPP 2016, Special Issue 2 of 2. ACM Trans. Parallel Comput. 4(1): 1:1-1:2 (2017) - [j14]Grey Ballard, Mary W. Hall, Tim Harris, Brandon Lucia:
Guest Editor Introduction PPoPP 2016, Special Issue 2 of 2. ACM Trans. Parallel Comput. 4(2): 6:1-6:2 (2017) - [c21]Edgar Solomonik, Grey Ballard, James Demmel, Torsten Hoefler:
A Communication-Avoiding Parallel Algorithm for the Symmetric Eigenvalue Problem. SPAA 2017: 111-121 - [i19]Casey Battaglino, Grey Ballard, Tamara G. Kolda:
A Practical Randomized CP Tensor Decomposition. CoRR abs/1701.06600 (2017) - [i18]Grey Ballard, Nicholas Knight, Kathryn Rouse:
Communication Lower Bounds for Matricized Tensor Times Khatri-Rao Product. CoRR abs/1708.07401 (2017) - [i17]Koby Hayashi, Grey Ballard, Jeffrey Jiang, Michael J. Tobia:
Shared Memory Parallelization of MTTKRP for Dense Tensors. CoRR abs/1708.08976 (2017) - 2016
- [j13]Grey Ballard, Austin R. Benson, Alex Druinsky, Benjamin Lipshitz, Oded Schwartz:
Improving the Numerical Stability of Fast Matrix Multiplication. SIAM J. Matrix Anal. Appl. 37(4): 1382-1418 (2016) - [j12]Grey Ballard, Christopher M. Siefert, Jonathan J. Hu:
Reducing Communication Costs for Sparse Matrix Multiplication within Algebraic Multigrid. SIAM J. Sci. Comput. 38(3) (2016) - [j11]Ariful Azad, Grey Ballard, Aydin Buluç, James Demmel, Laura Grigori, Oded Schwartz, Sivan Toledo, Samuel Williams:
Exploiting Multiple Levels of Parallelism in Sparse Matrix-Matrix Multiplication. SIAM J. Sci. Comput. 38(6) (2016) - [j10]Grey Ballard, Alex Druinsky, Nicholas Knight, Oded Schwartz:
Hypergraph Partitioning for Sparse Matrix-Matrix Multiplication. ACM Trans. Parallel Comput. 3(3): 18:1-18:34 (2016) - [c20]Woody Austin, Grey Ballard, Tamara G. Kolda:
Parallel Tensor Compression for Large-Scale Scientific Data. IPDPS 2016: 912-922 - [c19]Ramakrishnan Kannan, Grey Ballard, Haesun Park:
A high-performance parallel algorithm for nonnegative matrix factorization. PPoPP 2016: 9:1-9:11 - [c18]Grey Ballard, James Demmel, Andrew Gearhart, Benjamin Lipshitz, Yishai Oltchik, Oded Schwartz, Sivan Toledo:
Network Topologies and Inevitable Contention. COMHPC@SC 2016: 39-52 - [i16]Grey Ballard, Alex Druinsky, Nicholas Knight, Oded Schwartz:
Hypergraph Partitioning for Sparse Matrix-Matrix Multiplication. CoRR abs/1603.05627 (2016) - [i15]Edgar Solomonik, Grey Ballard, James Demmel, Torsten Hoefler:
A communication-avoiding parallel algorithm for the symmetric eigenvalue problem. CoRR abs/1604.03703 (2016) - [i14]Ramakrishnan Kannan, Grey Ballard, Haesun Park:
MPI-FAUN: An MPI-Based Framework for Alternating-Updating Nonnegative Matrix Factorization. CoRR abs/1609.09154 (2016) - 2015
- [j9]Grey Ballard, James Demmel, Laura Grigori, Mathias Jacquelin, Nicholas Knight, Hong Diep Nguyen:
Reconstructing Householder vectors from Tall-Skinny QR. J. Parallel Distributed Comput. 85: 3-31 (2015) - [j8]Grey Ballard, James Demmel, Nicholas Knight:
Avoiding Communication in Successive Band Reduction. ACM Trans. Parallel Comput. 1(2): 11:1-11:37 (2015) - [c17]Grey Ballard, Tamara G. Kolda, Ali Pinar, C. Seshadhri:
Diamond Sampling for Approximate Maximum All-Pairs Dot-Product (MAD) Search. ICDM 2015: 11-20 - [c16]Austin R. Benson, Grey Ballard:
A framework for practical parallel fast matrix multiplication. PPoPP 2015: 42-53 - [c15]Grey Ballard, Alex Druinsky, Nicholas Knight, Oded Schwartz:
Brief Announcement: Hypergraph Partitioning for Parallel Sparse Matrix-Matrix Multiplication. SPAA 2015: 86-88 - [i13]Grey Ballard, Ali Pinar, Tamara G. Kolda, C. Seshadhri:
Diamond Sampling for Approximate Maximum All-pairs Dot-product (MAD) Search. CoRR abs/1506.03872 (2015) - [i12]Grey Ballard, Austin R. Benson, Alex Druinsky, Benjamin Lipshitz, Oded Schwartz:
Improving the numerical stability of fast matrix multiplication algorithms. CoRR abs/1507.00687 (2015) - [i11]Ramakrishnan Kannan, Grey Ballard, Haesun Park:
A High-Performance Parallel Algorithm for Nonnegative Matrix Factorization. CoRR abs/1509.09313 (2015) - [i10]Ariful Azad, Grey Ballard, Aydin Buluç, James Demmel, Laura Grigori, Oded Schwartz, Sivan Toledo, Samuel Williams:
Exploiting Multiple Levels of Parallelism in Sparse Matrix-Matrix Multiplication. CoRR abs/1510.00844 (2015) - [i9]Woody Austin, Grey Ballard, Tamara G. Kolda:
Parallel Tensor Compression for Large-Scale Scientific Data. CoRR abs/1510.06689 (2015) - 2014
- [j7]Grey Ballard, Erin C. Carson, James Demmel, Mark Hoemmen, Nicholas Knight, Oded Schwartz:
Communication lower bounds and optimal algorithms for numerical linear algebra. Acta Numer. 23: 1-155 (2014) - [j6]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Communication costs of Strassen's matrix multiplication. Commun. ACM 57(2): 107-114 (2014) - [j5]Grey Ballard, Dulceneia Becker, James Demmel, Jack J. Dongarra, Alex Druinsky, Inon Peled, Oded Schwartz, Sivan Toledo, Ichitaro Yamazaki:
Communication-Avoiding Symmetric-Indefinite Factorization. SIAM J. Matrix Anal. Appl. 35(4): 1364-1406 (2014) - [c14]Grey Ballard, James Demmel, Laura Grigori, Mathias Jacquelin, Hong Diep Nguyen, Edgar Solomonik:
Reconstructing Householder Vectors from Tall-Skinny QR. IPDPS 2014: 1159-1170 - [i8]Austin R. Benson, Grey Ballard:
A Framework for Practical Parallel Fast Matrix Multiplication. CoRR abs/1409.2908 (2014) - 2013
- [b1]Grey Ballard:
Avoiding Communication in Dense Linear Algebra. University of California, Berkeley, USA, 2013 - [c13]Grey Ballard, Dulceneia Becker, James Demmel, Jack J. Dongarra, Alex Druinsky, Inon Peled, Oded Schwartz, Sivan Toledo, Ichitaro Yamazaki:
Implementing a Blocked Aasen's Algorithm with a Dynamic Scheduler on Multicore Architectures. IPDPS 2013: 895-907 - [c12]Grey Ballard, Aydin Buluç, James Demmel, Laura Grigori, Benjamin Lipshitz, Oded Schwartz, Sivan Toledo:
Communication optimal parallel multiplication of sparse random matrices. SPAA 2013: 222-231 - [c11]Grey Ballard, James Demmel, Benjamin Lipshitz, Oded Schwartz, Sivan Toledo:
Communication efficient gaussian elimination with partial pivoting using a shape morphing data layout. SPAA 2013: 232-240 - 2012
- [j4]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Graph expansion and communication costs of fast matrix multiplication. J. ACM 59(6): 32:1-32:23 (2012) - [c10]Grey Ballard, James Demmel, Olga Holtz, Benjamin Lipshitz, Oded Schwartz:
Graph Expansion Analysis for Communication Costs of Fast Rectangular Matrix Multiplication. MedAlg 2012: 13-36 - [c9]Grey Ballard, James Demmel, Nicholas Knight:
Communication avoiding successive band reduction. PPoPP 2012: 35-44 - [c8]Benjamin Lipshitz, Grey Ballard, James Demmel, Oded Schwartz:
Communication-avoiding parallel strassen: implementation and performance. SC 2012: 101 - [c7]Grey Ballard, James Demmel, Olga Holtz, Benjamin Lipshitz, Oded Schwartz:
Brief announcement: strong scaling of matrix multiplication algorithms and memory-independent communication lower bounds. SPAA 2012: 77-79 - [c6]Grey Ballard, James Demmel, Olga Holtz, Benjamin Lipshitz, Oded Schwartz:
Communication-optimal parallel algorithm for strassen's matrix multiplication. SPAA 2012: 193-204 - [i7]Grey Ballard, James Demmel, Olga Holtz, Benjamin Lipshitz, Oded Schwartz:
Communication-Optimal Parallel Algorithm for Strassen's Matrix Multiplication. CoRR abs/1202.3173 (2012) - [i6]Grey Ballard, James Demmel, Olga Holtz, Benjamin Lipshitz, Oded Schwartz:
Strong Scaling of Matrix Multiplication Algorithms and Memory-Independent Communication Lower Bounds. CoRR abs/1202.3177 (2012) - [i5]Grey Ballard, James Demmel, Olga Holtz, Benjamin Lipshitz, Oded Schwartz:
Graph Expansion Analysis for Communication Costs of Fast Rectangular Matrix Multiplication. CoRR abs/1209.2184 (2012) - 2011
- [j3]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Minimizing Communication in Numerical Linear Algebra. SIAM J. Matrix Anal. Appl. 32(3): 866-901 (2011) - [c5]Michael J. Anderson, Grey Ballard, James Demmel, Kurt Keutzer:
Communication-Avoiding QR Decomposition for GPUs. IPDPS 2011: 48-58 - [c4]Grey Ballard, Tamara G. Kolda, Todd D. Plantenga:
Efficiently Computing Tensor Eigenvalues on a GPU. IPDPS Workshops 2011: 1340-1348 - [c3]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Graph expansion and communication costs of fast matrix multiplication: regular submission. SPAA 2011: 1-12 - [c2]Grey Ballard, James Demmel, Andrew Gearhart:
Brief announcement: communication bounds for heterogeneous architectures. SPAA 2011: 257-258 - [i4]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Graph Expansion and Communication Costs of Fast Matrix Multiplication. CoRR abs/1109.1693 (2011) - 2010
- [j2]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Communication-optimal Parallel and Sequential Cholesky Decomposition. SIAM J. Sci. Comput. 32(6): 3495-3523 (2010) - [i3]Grey Ballard, James Demmel, Ioana Dumitriu:
Minimizing Communication for Eigenproblems and the Singular Value Decomposition. CoRR abs/1011.3077 (2010)
2000 – 2009
- 2009
- [c1]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Communication-optimal parallel and sequential Cholesky decomposition: extended abstract. SPAA 2009: 245-252 - [i2]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Communication-optimal Parallel and Sequential Cholesky Decomposition. CoRR abs/0902.2537 (2009) - [i1]Grey Ballard, James Demmel, Olga Holtz, Oded Schwartz:
Minimizing Communication in Linear Algebra. CoRR abs/0905.2485 (2009) - 2006
- [j1]Grey Ballard:
Modeling protein dependency networks using CoCoA. ACM Crossroads 13(1): 6 (2006)
Coauthor Index
manage site settings
To protect your privacy, all features that rely on external API calls from your browser are turned off by default. You need to opt-in for them to become active. All settings here will be stored as cookies with your web browser. For more information see our F.A.Q.
Unpaywalled article links
Add open access links from to the list of external document links (if available).
Privacy notice: By enabling the option above, your browser will contact the API of unpaywall.org to load hyperlinks to open access articles. Although we do not have any reason to believe that your call will be tracked, we do not have any control over how the remote server uses your data. So please proceed with care and consider checking the Unpaywall privacy policy.
Archived links via Wayback Machine
For web page which are no longer available, try to retrieve content from the of the Internet Archive (if available).
Privacy notice: By enabling the option above, your browser will contact the API of archive.org to check for archived content of web pages that are no longer available. Although we do not have any reason to believe that your call will be tracked, we do not have any control over how the remote server uses your data. So please proceed with care and consider checking the Internet Archive privacy policy.
Reference lists
Add a list of references from , , and to record detail pages.
load references from crossref.org and opencitations.net
Privacy notice: By enabling the option above, your browser will contact the APIs of crossref.org, opencitations.net, and semanticscholar.org to load article reference information. Although we do not have any reason to believe that your call will be tracked, we do not have any control over how the remote server uses your data. So please proceed with care and consider checking the Crossref privacy policy and the OpenCitations privacy policy, as well as the AI2 Privacy Policy covering Semantic Scholar.
Citation data
Add a list of citing articles from and to record detail pages.
load citations from opencitations.net
Privacy notice: By enabling the option above, your browser will contact the API of opencitations.net and semanticscholar.org to load citation information. Although we do not have any reason to believe that your call will be tracked, we do not have any control over how the remote server uses your data. So please proceed with care and consider checking the OpenCitations privacy policy as well as the AI2 Privacy Policy covering Semantic Scholar.
OpenAlex data
Load additional information about publications from .
Privacy notice: By enabling the option above, your browser will contact the API of openalex.org to load additional information. Although we do not have any reason to believe that your call will be tracked, we do not have any control over how the remote server uses your data. So please proceed with care and consider checking the information given by OpenAlex.
last updated on 2024-11-08 21:28 CET by the dblp team
all metadata released as open data under CC0 1.0 license
see also: Terms of Use | Privacy Policy | Imprint