A System of Modal Logicby Jan Łukasiewicz;A System of Modal Logicby Jan Łukasiewicz;Note on a Modal System of Łukasiewicz.by Ivo Thomas;The Interpretation of Two Systems of Modal Logicby A. N. Prior;On the Interpretation of a Modal System of Łukasiewicz.by Alan Ross Anderson;Arithmetic and Modal Logicby Jan Łukasiewicz;On a Controversial Problem of Aristotle's Modal Syllogistic Dominican Studiesby Jan Łukasiewicz