@article{RCM_1986__20_3-4_181768,
     author = {Osvaldo Acuna Ortega},
     title = {Sobre {Una} {Definicion} {De} {Cardinales} {Finitos} {En} {Un} {Topos} {Arbitrario.}},
     journal = {Revista colombiana de matematicas},
     pages = {79--104},
     publisher = {mathdoc},
     volume = {20},
     number = {3-4},
     year = {1986},
     zbl = {0653.18003},
     url = {http://geodesic.mathdoc.fr/item/RCM_1986__20_3-4_181768/}
}