1. Datatypen bezien vanuit de recursietheorie;Bergstra,1978
2. What is an abstract data type?;Bergstra;Inf. Proc. Lett.,1978
3. Equational specification of finite minimal unoids, using unary hidden functions only;Bergstra;Fund. Inf.,1982
4. Program algebra for component code;Bergstra;Formal Aspects Comput.,2000
5. Program algebra for sequential code;Bergstra;J. Logic Algebr. Programming,2002