J. Tang, H. fung Leung, Q. Luo, D. Chen, und J. Gong. Proceedings of the Twenty-First International Joint Conference on Artificial Intelligence, Seite 2089-2094. Pasadena, California, USA, (2009)
J. Baldwin, T. Martin, und J. Shanahan. Fuzzy Logic in Artificial Intelligence, IJCAI'97
Workshop, Selected and Invited Papers, Volume 1566 von Lecture Notes in Artificial Intelligence, Seite 91--116. Nagoya, Japan, Springer, (August 1997)Published 1999.