references

1) clojure.core.contracts references

• A Proof Engine for Eiffel
• An Axiomatic Basis for Computer Programming by C.A.R Hoare -- essential reading
• Behavioral Software Contracts (PDF) by Robert Bruce Findler
• Contract Programming in D
• Contract Soundness for Object-Oriented Languages by Robert Bruce Findler and Matthias Felleisen
• Contracts for Higher-order functions by Robert Bruce Findler and Matthias Felleisen
• Contracts in Racket (A Scheme Descendent)
• Design by Contract and Unit Testing
• Design by contract for Ruby
• Eiffel: The Language by Bertrand Meyer
• Fortress Language Specification (PDF) by Guy L. Steele Jr., et al.
• How to Deign Programs by Matthias Felleisen, Robert Bruce Findler, Matthew Flatt, and Shriram Krishnamurthi here
• Jass - Java with Assertions (PDF) by Detlef Bartetzko, Clemens Fischer, Michael Moller and Heike Wehrheim
• Object-oriented Software Construction by Bertrand Meyer
• System.Diagnostics.Contracts