Constraints on Null Values in Relational Databases

conf/vldb/81 Billie S. Goldstein Constraints on Null Values in Relational Databases VLDB81/P101.PDF 101-110 1981 VLDB db/conf/vldb/vldb81.html#Goldstein81 ... conf/vldb/BeeriBG78 conf/vldb/BernsteinG80 ... ... conf/vldb/Lien79 ... ... ... ... books/cs/Ullman80 conf/sigmod/Vassiliou79 ... ...