conf/sigmod/87 Hussien Aly Z. Meral Özsoyoglu Non-deterministic Modelling of Logical Queries in Deductive Databases. 60-72 1987 SIGMOD Conference db/conf/sigmod/sigmod87.html#AlyO87 SIGMOD87/P060.PDF http://doi.acm.org/10.1145/38713.38726 db/conf/sigmod/AlyO87.html ... conf/pods/BancilhonMSU86 conf/sigmod/BancilhonR86 conf/rta/ChoppyJ85 ... journals/jacm/HenschenN84 ... ... conf/pods/SaccaZ86 journals/tods/Ullman85