1. Woodcock, J.C.P., Cavalcanti, A.L.C.: A Concurrent Language for Refinement. In: 5th Irish Workshop on Formal Methods (2001)
2. Woodcock, J.C.P., Davies, J.: Using Z – Specification, Refinement, and Proof. Prentice-Hall, Englewood Cliffs (1996)
3. Hoare, C.A.R.: Communicating Sequential Processes. Prentice-Hall, Englewood Cliffs (1985)
4. Hoare, C.A.R., He, J.: Unifying Theories of Programming. Prentice-Hall, Englewood Cliffs (1998)
5. Oliveira, M.V.M.: A Refinement Calculus for Circus. PhD thesis, Department of Computer Science, The University of York (2005)