@article{Hoare85c,
  title = "A Couple of Novelties in the Propositional Calculus",
  author = "C.A.R. Hoare",
  year = "1985",
  journal = "Zeitschr. f. Math. Logik und Grundlagen d. Math.",
  number = "2",
  pages = "173--178",
  volume = "31",
}