M. Akbarzadeh-T., E. Tunstel, K. Kumbla, и M. Jamshidi. Proceedings of the 1998 IEEE World Congress on
Computational Intelligence, 2, стр. 1200--1205. Anchorage, Alaska, USA, IEEE Press, (5-9 May 1998)
T. Recio, и M. González-López. ISSAC '94: Proceedings of the 1994 International Symposium on Symbolic
and Algebraic Computation: July 20--22, 1994, Oxford, England, United
Kingdom, стр. 354--358. New York, NY 10036, USA, ACM Press, (1994)
M. Cerulli, E. Chioccariello, и E. Lemut. Proceedings of CERME 4, Fourth Congress of the European Society for Research in Mathematics Education 17 - 21 February 2005 in Sant Feliu de Guíxols, Spain YERME day: 16- 17 February., ERME, (февраля 2005)