Susan Stepney, Rosalind Barden, David Cooper.
A survey of object orientation in Z.

Software Engineering Journal 7(2):150-160, 1992.

Abstract

Two technologies offer much to the software industry; formal specification aids precision and object orientation aids structuring. One popular formal specification language is Z. The paper surveys techniques for adding object-oriented structuring to Z and looks at three of them in more detail

@article(Stepney+Barden+Cooper:1992:OOZ,
  author = "Susan Stepney and Rosalind Barden and David Cooper",
  title = "A survey of object orientation in {Z}",
  journal = "Software Engineering Journal",
  pages = "150-160",
  volume = 7,
  number = 2,
  year = 1992 
)