1. http://hackage.haskell.org/package/free-theorems
. Accessed Sept 2019
2. http://free-theorems.nomeata.de
. Accessed Sept 2019
3. http://hackage.haskell.org/package/lambdabot-haskell-plugins
. Accessed Sept 2019
4. http://hackage.haskell.org/package/ft-generator
. Accessed Sept 2019
5. Bainbridge, E., Freyd, P., Scedrov, A., Scott, P.: Functorial polymorphism. Theor. Comput. Sci. 70(1), 35–64 (1990)