Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{MASLO_1974__24_2_a7, author = {Jakub{\'\i}k, J\'an}, title = {Quasiorder on {Systems} of {Directed} {Sets}}, journal = {Mathematica slovaca}, pages = {173--177}, publisher = {mathdoc}, volume = {24}, number = {2}, year = {1974}, mrnumber = {0351925}, zbl = {0281.06003}, language = {en}, url = {http://geodesic.mathdoc.fr/item/MASLO_1974__24_2_a7/} }
Jakubík, Ján. Quasiorder on Systems of Directed Sets. Mathematica slovaca, Tome 24 (1974) no. 2, pp. 173-177. http://geodesic.mathdoc.fr/item/MASLO_1974__24_2_a7/