1. Baader, F. and Nipkow, T., Term Rewriting and All That. Cambridge University Press, Cambridge, 1998.
2. Buchberger, B., Gröbner bases: An algorithmic method in polynomial ideal theory. In: Recent Trends in Multidimensional Systems Theory (Bose, N. K., ed.), pp. 184–232. D. Reidel, Dordrecht, Holland, 1985.
3. James, E. M. and Lloyd, N. G., A cubic system with eight small-amplitude limit cycles. IMA J. Appl. Math. 47: 163–171, 1991.
4. Li, W., An open logic system (in Chinese). Science in China (Sci. Sinica) (ser. A) 10: 1103–1113, 1992.
5. Li, W. and Ma, S., A framework for analytic-intelligent agents. In: Proceedings of the International Conference on Artificial Intelligence (IC-AI’2000), Las Vegas, USA, 2000.