@inproceedings{DBLP:conf/er/Tardo79,
  author    = {J. J. Tardo},
  title     = {Domains and Data Types in ERA Information Model},
  booktitle = {ER},
  year      = {1979},
  pages     = {409-412},
  crossref  = {DBLP:conf/er/79},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}

@proceedings{DBLP:conf/er/79,
  editor    = {Peter P. Chen},
  title     = {Entity-Relationship Approach to Systems Analysis and Design.
                Proc. 1st International Conference on the Entity-Relationship
               Approach},
  publisher = {North-Holland},
  year      = {1980},
  isbn      = {0-444-85487-8},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}