Engeli M. E. "A Language and List Structure for an Algebraic Manipulation System"

Bobrow, D. G. (ed) (1968) Bobrow, D. G. (ed) "Symbol Manipulation Languages and Techniques", Proceedings of the IFIP Working Conference on Symbol Manipulation Languages. North-Holland Publishing Co., Amsterdam, 1968   Max Engeli

Languages mentioned SYMBAL {1967} An extension of ALGOL to do formal algebraic manipulation.