K. Lang. Proceedings of the 12th International Conference on Machine Learning, Seite 331--339. Morgan Kaufmann publishers Inc.: San Mateo, CA, USA, (1995)
R. Agrawal, und R. Srikant. VLDB '94: Proceedings of the 20th International Conference on Very Large Data Bases, Seite 487--499. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (1994)