@article{ABM79,
  year    = {1979},
  author  = {Krzysztof R. Apt and Jan A. Bergstra and Lambert Meertens},
  title   = {Recursive assertions are not enough---or are they?},
  journal = {Theoretical Computer Science},
  volume  = {8},
  pages   = {73--87},
  pubcat  = {journal},
}