@article{1077472382,
author = {Day, Mahlon M.},
title = {Oriented systems},
journal = {Duke Math. J.},
volume = {11},
number = {1},
year = {1944},
pages = { 201-229},
language = {en},
url = {http://dml.mathdoc.fr/item/1077472382}
}
Day, Mahlon M. Oriented systems. Duke Math. J., Tome 11 (1944) no. 1, pp. 201-229. http://gdmltest.u-ga.fr/item/1077472382/