- Diehl, Stephen.[2.3] What I Wish I Knew When Learning Haskell.
- Diehl, Stephen [ ] Hindley-Milner Inference
- Grabmüller, Martin  'Algorithm W Step by Step.' https://github.com/wh5a/Algorithm-W-Step-By-Step/blob/master/AlgorithmW.pdf
- Grabmüller, Martin  'Monad Transformers Step by Step.' [This will help you with the Algorithm W code (unless you do not need it by virtue of being an expert in Monad Transformers).]
- Heeren, Bastiaan; Hage, Jurriaan; and Swierstra, Doaitse , 'Generalizing Hindley-Milner Type Inference Algorithms.'
- Lynn, Ben [ ] Haskell Fan Site and Lambda Calculus
- Pierce, Benjamin C. , Types and Programming Languages.