@article{MAN_1924__92_159069,
     author = {P. Urysohn and P. Alexandroff},
     title = {Zur {Theorie} der topologischen {R\"aume}},
     journal = {Mathematische Annalen},
     pages = {258--266},
     publisher = {mathdoc},
     volume = {92},
     year = {1924},
     zbl = {50.0128.06},
     url = {http://geodesic.mathdoc.fr/item/MAN_1924__92_159069/}
}