@article{1093635503,
author = {Shannon, Gary P.},
title = {Provable forms of Martin's axiom.},
journal = {Notre Dame J. Formal Logic},
volume = {31},
number = {2},
year = {1990},
pages = { 382-388},
language = {en},
url = {http://dml.mathdoc.fr/item/1093635503}
}
Shannon, Gary P. Provable forms of Martin's axiom.. Notre Dame J. Formal Logic, Tome 31 (1990) no. 2, pp. 382-388. http://gdmltest.u-ga.fr/item/1093635503/