1. , and , Design and Analysis of Computer Algorithms, Addison-Wesley, Reading, Massachusetts, 1974.
2. and , Algorithmic Language and Program Development, Springer-Verlag, Berlin, 1982.
3. and , Models and Ultraproducts, North-Holland, Amsterdam, 1969.
4. , and , The DevaWEB System, Technical Report 93–39, Technische Universität Berlin, December 1993.