The nested universal relation database model

Logic programming

First Russian Conference on Logic Programming, Irkutsk, Russia, September 14-18, 1990

Parallel computation

First International ACPC Conference, Salzburg, Austria, September 30-October 2, 1991

Parallel execution of Parlog

Database systems of the 90s

international symposium, Müggelsee, Berlin, FRG, November 5-7, 1990