Statistical Estimators for Relational Algebra Expressions. - Wen-Chi Hou; Gultekin Özsoyoglu; Baldeo K. Taneja (PODS, 1988)

Processing Aggregate Relational Queries with Hard Time Constraints. - Wen-Chi Hou; Gultekin Özsoyoglu; Baldeo K. Taneja (SIGMOD Conference, 1989)