Kim B. Bruce Angela Schuett Robert van Gent Adrian Fiech PolyTOIL: A type-safe polymorphic object-oriented language. 225-290 2003 25 ACM Trans. Program. Lang. Syst. 2 http://doi.acm.org/10.1145/641888.641891 db/journals/toplas/toplas25.html#BruceSGF03