@article{1093635417, author = {Buss, Samuel R.}, title = {The modal logic of pure provability.}, journal = {Notre Dame J. Formal Logic}, volume = {31}, number = {2}, year = {1990}, pages = { 225-231}, language = {en}, url = {http://dml.mathdoc.fr/item/1093635417} }
Buss, Samuel R. The modal logic of pure provability.. Notre Dame J. Formal Logic, Tome 31 (1990) no. 2, pp. 225-231. http://gdmltest.u-ga.fr/item/1093635417/