1. J.C.M.Baeten, J.A.Bergstra & J.W.Klop, Conditional axioms and α/β-calculus in process algebra, report CS-R8502, Centre for Math. & Comp. Sci., Amsterdam 1985, to appear in: Proc. IFIP Conf. on Formal Description of Progr. Concepts (M.Wirsing, ed.), Gl. Avernæs 1986, North-Holland.
2. J.C.M.Baeten, J.A.Bergstra & J.W.Klop, On the consistency of Koomen's fair abstraction rule, to appear in Theor. Comp. Sci. 51 (1/2).
3. J.C. Baeten & R.J. van Glabbeek, Another look at abstraction in process algebra, report CS-R8701, Centre for Math. & Comp. Sci., Amsterdam 1987.
4. J.A. Bergstra & J.W. Klop, Process algebra for synchronous communication, Inf. & Control 60 (1/3), pp. 109–137, 1984.
5. J.A. Bergstra & J.W. Klop, Algebra of communicating processes with abstraction, Theor. Comp. Sci. 37 (1), pp. 77–121, 1985.