John V. Guttag, James J. Horning, John Williams. FP with data abstraction and strong typing. In Arvind, Jack B. Dennis, editors, Proceedings of the 1981 conference on Functional programming languages and computer architecture, FPCA 1981, Wentworth, New Hampshire, USA, October 1981. pages 11-24, ACM, 1981. [doi]
Abstract is missing.