1. Algebraic specifications of computable and semicomputable data structures;Bergstra;Mathematical Centre, Department of Computer Science, Research Report IW 115/79,1979
2. A natural data type with a finite equational final semantics specification, but no effective equational initial specification;Bergstra;Bull. EATCS,1980
3. A characterisation of computable data types by means of a finite equational specification method;Bergstra,1980
4. Initial and final algebra semantics for data type specifications: two characterisation theorems;Bergstra;SIAM J. Comput.,1983
5. The completeness of the algebraic specification methods for computable data types;Bergstra;Inform. and Control,1983