J. Sroka, P. Włodarczyk, \. Krupa, and J. Hidders. Proceedings of the 1st International Workshop on Workflow Approaches to New Data-centric Science, page 5:1--5:6. New York, NY, USA, ACM, (2010)
L. Wong. PODS '93: Proceedings of the twelfth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems, page 26--36. New York, NY, USA, ACM Press, (1993)