@article{PDML_1979__16_3-4_67_0,
     author = {Mayer, Jean},
     title = {Un nouveau type de preuve math\'ematique : le th\'eor\`eme des quatre couleurs. {I} - {Expos\'e} pr\'eliminaire},
     journal = {Publications du D\'epartement de math\'ematiques (Lyon)},
     pages = {67--80},
     publisher = {Universit\'e Claude Bernard - Lyon 1},
     volume = {16},
     number = {3-4},
     year = {1979},
     mrnumber = {602655},
     zbl = {0455.05030},
     language = {fr},
     url = {http://www.numdam.org/item/PDML_1979__16_3-4_67_0/}
}