Ulf Norell, Patrik Jansson. Polytypic Programming in Haskell. In Philip W. Trinder, Greg Michaelson, Ricardo Pena, editors, Implementation of Functional Languages, 15th International Workshop, IFL 2003, Edinburgh, UK, September 8-11, 2003, Revised Papers. Volume 3145 of Lecture Notes in Computer Science, pages 168-184, Springer, 2003. [doi]