S. Doaitse Swierstra Programming Languages and Systems, 8th European Symposium on Programming, ESOP'99, Held as Part of the European Joint Conferences on the Theory and Practice of Software, ETAPS'99, Amsterdam, The Netherlands, 22-28 March, 1999, Proceedings ESOP Lecture Notes in Computer Science 1576 Springer 1999 3-540-65699-5 https://doi.org/10.1007/3-540-49099-X db/conf/esop/esop99.html