conf/vldb/81 Donald D. Chamberlin A. M. Gilbert Robert A. Yost A History of System R and SQL/Data System (Invited Paper) VLDB81/P456.PDF 456-464 1981 VLDB db/conf/vldb/vldb81.html#ChamberlinGY81 db/conf/vldb/ChamberlinGY81.html journals/cacm/AstrahanC75 journals/tods/AstrahanBCEGGKLMMPTWW76 conf/ifip/AstrahanSK80 journals/cacm/ChamberlinABGKLLMPPSSSTWY81 journals/sigops/BlasgenGMP79 ... conf/sigmod/ChamberlinB74 ... journals/tods/ChamberlinAKLMPSSSWY81 conf/icod/Chamberlin80 journals/cacm/Codd70 persons/Codd71a conf/pacific/Codd75 journals/tods/Codd79 journals/csur/Comer79 journals/tods/Fagin78 ... ... conf/ac/Gray78 journals/csur/GrayMBLLPPT81 journals/tods/GriffithsW76 ... ... ... ... ... conf/sigmod/SelingerACLP79 conf/sigmod/Stonebraker75