@article{1183736434, author = {Zeman, J. Jay}, title = {Lemmon-Style Bases for the Systems $S1^\circ - S4^\circ$}, journal = {J. Symbolic Logic}, volume = {33}, number = {1}, year = {1968}, pages = { 458-461}, language = {en}, url = {http://dml.mathdoc.fr/item/1183736434} }
Zeman, J. Jay. Lemmon-Style Bases for the Systems $S1^\circ - S4^\circ$. J. Symbolic Logic, Tome 33 (1968) no. 1, pp. 458-461. http://gdmltest.u-ga.fr/item/1183736434/