@article{1093891401,
author = {Gleason, Gary Gilford},
title = {Normal and skew systems.},
journal = {Notre Dame J. Formal Logic},
volume = {15},
number = {1},
year = {1974},
pages = { 379-401},
language = {en},
url = {http://dml.mathdoc.fr/item/1093891401}
}
Gleason, Gary Gilford. Normal and skew systems.. Notre Dame J. Formal Logic, Tome 15 (1974) no. 1, pp. 379-401. http://gdmltest.u-ga.fr/item/1093891401/