Report to X3 DDL - External versus Internal Format.

http://doi.acm.org/10.1145/984409.984412 Calvin N. Mooers Report to X3 DDL - External versus Internal Format. 37 sigmodR/01-1/P037.pdf 1969 1 FDT - Bulletin of ACM SIGFIDET 1 db/journals/sigmod/sigmod1.html#Mooers69b