1. On the power of algebraic specifications;Bergstra,1981
2. On specifying sets of integers;Bergstra,1980
3. On the adequacy of finite equational methods for data type specification;Bergstra;SIGPLAN Notices,1979
4. Initial and final algebra semantics for data type specification: Two characterization theorems;Bergstra,1980
5. Model-theoretic aspects of abstract data specification;Bertoni;26th Coll. on Math. Logic in Programming,1978