conf/pods/87 Raghu Ramakrishnan François Bancilhon Abraham Silberschatz Safety of Recursive Horn Clauses With Infinite Relations. 328-339 1987 PODS db/conf/pods/pods87.html#RamakrishnanBS87 http://doi.acm.org/10.1145/28659.28694 journals/anthology/cd1-3:PODS87/P328.PDF journals/anthology/dvd1:text/1-3/PODS87/P328.PDF conf/pods/AfratiPPRSU86 ... ... books/cs/Ullman82 ... conf/eds/Zaniolo86