- J. E. Nicholls, editor, Z User Workshop, York, UK, 16-17 December 1991, Proceedings. Workshops in Computing, Springer, 1992.
- Susan Stepney, Rosalind Barden, David Cooper, editors, Object Orientation in Z. Workshops in Computing, Springer, 1992.
- Jonathan P. Bowen, J. E. Nicholls, editors, Z User Workshop, London, UK, 14-15 December 1992, Proceedings. Workshops in Computing, Springer, 1992.