Stepney, S., Cooper, D.
& Woodcock, J. (1998).
More Powerful Z Data Refinement: Pushing the State of the Art in Industrial Refinement. In J. P. Bowen, A. Fett & M. G. Hinchey (Eds.),
ZUM ’98: The Z Formal Specification Notation: 11th International Conference of Z Users, Berlin, Germany, September 24-26, 1998. Proceedings (Vol. 1, pp. 284-307). Springer Berlin, Heidelberg.
https://doi.org/10.1007/978-3-540-49676-2_20