@book{OPUS4-88030,
  title     = {Formal program development: IFIP TC 2/WG 2 1 state of the art report},
  editor    = {Bernhard M{\"o}ller and Helmut Partsch and Steve Schuman},
  isbn      = {9783540574996},
  doi       = {10.1007/3-540-57499-9},
  year      = {1993},
}