Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{PMFA_1979__24_4_a0, author = {Bos\'ak, Juraj}, title = {Ako bol vyrie\v{s}en\'y probl\'em \v{s}tyroch farieb}, journal = {Pokroky matematiky, fyziky a astronomie}, pages = {181--201}, publisher = {mathdoc}, volume = {24}, number = {4}, year = {1979}, mrnumber = {0549596}, zbl = {0424.05025}, language = {sl}, url = {http://geodesic.mathdoc.fr/item/PMFA_1979__24_4_a0/} }
Bosák, Juraj. Ako bol vyriešený problém štyroch farieb. Pokroky matematiky, fyziky a astronomie, Tome 24 (1979) no. 4, pp. 181-201. http://geodesic.mathdoc.fr/item/PMFA_1979__24_4_a0/