ACM Transactions on Programming Languages and Systems March 1996: Vol 18, Nr 2 p 109 Type Classes in Haskell by C. Hall, K. Hammond, S. Peyton Jones and Ph. Wadler p 103 Handling Floating-Point Exceptions in Numeric Programs by J. Hauser p 175 Total Correctness by Local Improvement in the Transformation of Functional Programs by D. Sands