@article{MSH_1975__51__51_0,
     author = {Lanz, M. F. and Martin, P.},
     title = {Les $1$-graphes finis et leurs morphismes},
     journal = {Math\'ematiques et sciences humaines},
     pages = {51--75},
     publisher = {Ecole Pratique des hautes \'etudes, Centre de math\'ematique sociale et de statistique},
     volume = {51},
     year = {1975},
     mrnumber = {401485},
     zbl = {0326.05101},
     language = {fr},
     url = {http://archive.numdam.org/item/MSH_1975__51__51_0/}
}