1. An algebraic study of Diodorean modal systems;Bull;The journal of symbolic logic,1965
2. An algebraic study of tense logics with linear time;Bull;The journal of symbolic logic,1968
3. Modal logics between S4 and S5;Dummett;Zeitschrift für mathematische Logik und Grundlagen der Mathematik,1959
4. There are infinitely many Diodorean modal functions;Makinson;The journal of symbolic logic,1966