title: efficient approximation of optimization queries under parametric aggregation constraints. authors: dimitrios gunopulos , nick koudas , divesh srivastava , michail vlachos , sudipto guha. venue: vldb. year: 2003
title: optimization of constrained frequent set queries with 2-variable constraints. authors: laks v. s. lakshmanan , raymond ng , jiawei han , alex pang. venue: international conference on management of data. year: 1999