Butler G. and Cannon J.J., "Cayley version 4: The user language"

Gianni P. (1989) Gianni P. (ed), Proceedings of the 1988 International Symposium on Symbolic and Algebraic Computation, Rome, July 4- 8, 1988, LNCS 358, Springer, New York, 1989  

Languages mentioned CAYLEY {1975} Symbolic maths for group theory