1. Meseguer, J., and Goguen, J.A.: ‘Initiality, induction and computability’, Algebraic methods in semantics, (Cambridge University Press 1984), p. 459–541
2. ‘Introducing OBJ3’, Technical Report, SRI-CSL-88-9, SRI International, August, 1988 (to appear in Case Studies in Algebraic Specification Using OBJ)
3. ‘Order-sorted algebra I: partial and overloaded operators, errors and inheritance’, Technical Report, SRI International, 1987
4. ‘Operational semantics of OBJ3’, Technical Report, 87-R-87, Centre de Recherche en Informatique de Nancy, 1987 (see also Proc. ICALP '88, Tampere, July 1988, Springer-Verlag)