@article{SD_1960-1961__14_2_A6_0,
     author = {Bor\r{u}vka, Otakar},
     title = {D\'ecompositions dans les ensembles et th\'eorie des groupo{\"\i}des},
     journal = {S\'eminaire Dubreil. Alg\`ebre et th\'eorie des nombres},
     note = {talk:22 bis},
     pages = {19--35},
     publisher = {Secr\'etariat math\'ematique},
     volume = {14},
     number = {2},
     year = {1960-1961},
     language = {fr},
     url = {http://archive.numdam.org/item/SD_1960-1961__14_2_A6_0/}
}