- P. Wadler and S. Blott. How to make ad-hoc polymorphism less ad hoc. http://www.cse.iitk.ac.in/users/karkare/courses/2010/cs653/Papers/ad-hoc-polymorphism.pdf
- Cordelia V. Hall, Kevin Hammond, Simon L. Peyton Jones, and Philip L. Wadler. Typeclasses in Haskell. http://ropas.snu.ac.kr/lib/dock/HaHaJoWa1996.pdf