Programming Languages and Systems 8th European Symposium on Programming, ESOP'99 Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS'99, Amsterdam, The Netherlands, March 22-28, 1999 Proceedings - Swierstra, S. Doaitse; Swierstra, S. Doaitse (Springer Berlin Heidelberg : Imprint: Springer, 1999)