conf/sigmod/79 Ronald Fagin Normal Forms and Relational Database Operators. 153-160 1979 SIGMOD Conference db/conf/sigmod/sigmod79.html#Fagin79 SIGMOD79/P153.PDF http://doi.acm.org/10.1145/582095.582120 journals/tods/AstrahanBCEGGKLMMPTWW76 conf/focs/AhoBU77 journals/siamcomp/AhoSU79 conf/ifip/Armstrong74 conf/vldb/BeeriBG78 journals/tods/Bernstein76 conf/mfcs/Cadiou76 journals/cacm/Codd70 persons/Codd72 conf/ifip/Codd74 ... ... journals/tods/Fagin77 ... conf/sigmod/Heath71 ... conf/vldb/Nicolas78 journals/tods/Rissanen77 conf/mfcs/Rissanen78 conf/vldb/Smith78b