M. Rapkin, и O. Abu-Gheida. AFIPS Fall Joint Computing Conference (1), том 33 из AFIPS Conference Proceedings, стр. 731-746. AFIPS / ACM / Thomson Book Company, Washington D.C., (1968)
O. Hegazy, A. Bastawisi, и R. Ibrahim. International Conference on Computational Intelligence, стр. 354-360. International Computational Intelligence Society, (2004)