1. J. J. Blaszczuk andW. Dziobiak,Modal systems related to S4 n of Sobociński,Bulletin of the Section of Logic, Polish Academy of Sciences, Institute of Philosophy and Sociology. Vol. 4 No. 3 (1975), pp. 103–108.
2. J. J. Blaszczuk andW. Dziobiak.Modal systems “placed” in the triangle S4−T 1 * −T,Bulletin of the Section of Logic, Polish Academy of Sciences, Institute of Philosophy and Sociology, Vol. 4 No. 4, (1975), pp. 138–142.
3. J. J. Blaszczuk andW. Dziobiak,An axiomatization of M n-counterparts for some modal calculi,Reports on Mathematical Logic, Vol. 6 (1976), pp. 3–6.
4. W. Dziobiak,Kripke's style semantics for some modal systems.Bulletin of Section of Logic, Polish Academy of Sciences, Institute of Philosophy and Sociology Vol. 5, No. 2, (1976), pp. 63–67.
5. T. Furmanowski,Remarks on discussive propositional calculus,Studia Logica, Vol. XXXIV, (1975), No. 1, pp. 39–43.