@article{1093891703,
author = {Fine, Kit},
title = {Normal forms in modal logic.},
journal = {Notre Dame J. Formal Logic},
volume = {16},
number = {1},
year = {1975},
pages = { 229-237},
language = {en},
url = {http://dml.mathdoc.fr/item/1093891703}
}
Fine, Kit. Normal forms in modal logic.. Notre Dame J. Formal Logic, Tome 16 (1975) no. 1, pp. 229-237. http://gdmltest.u-ga.fr/item/1093891703/