1. Angius, N., Stefaneas, P.: The Logical Structure of Modular Semantic Theories of Software Systems. J. Log. Comput (Forthcoming)
2. Barwise, J.K.: Axioms for abstract model theory. Ann. Math. Log. 7(2), 221–265 (1974)
3. Baier, C., Katoen, J.P.: Principles of model checking. MIT press, Cambridge (2008)
4. Burstall, R.M., Goguen, J.A.: Putting theories together to make specifications. In: Proceedings of the 5th International Joint Conference on Artificial Intelligence, Volume 2, pp. 1045–1058. Morgan Kaufmann, San Francisco (1977)
5. Burstall, R.M., Goguen, J.A.: The semantics of Clear, a specification language. In: Abstract Software Specifications, pp. 292–332, Springer, Heidelberg (1980)