@inproceedings{DBLP:conf/sigmod/Codd71,
author = {E. F. Codd},
title = {A Database Sublanguage Founded on the Relational Calculus},
booktitle = {SIGFIDET Workshop},
year = {1971},
pages = {35-68},
crossref = {DBLP:conf/sigmod/71},
bibsource = {DBLP, http://dblp.uni-trier.de}
}
@proceedings{DBLP:conf/sigmod/71,
editor = {E. F. Codd and
A. L. Dean},
title = {Proceedings of 1971 ACM-SIGFIDET Workshop on Data Description,
Access and Control, San Diego, California, November 11-12,
1971},
publisher = {ACM},
year = {1971},
bibsource = {DBLP, http://dblp.uni-trier.de}
}