Benjamin W. Wah Yi Shang Zhe Wu Discrete Lagrangian Method for Optimizing the Design of Multiplierless QMF Filter Banks. 529- 1997 conf/asap/1997 ASAP http://doi.ieeecomputersociety.org/10.1109/ASAP.1997.606858 db/conf/asap/asap1997.html#WahSW97