@Article{MS06,
    Author       = "M{\"o}ller, B. and Struth, G.",
    Year         = "2006",
    Title        = "{Algebras of Modal Operators and Partial Correctness}",
    Journal      = "Theoretical Computer Science",
    Volume       = "351",
    Number       = "2",
    Pages        = "221-239",
    Comment      = "TPTPRef"
}