@article{DAN_1971_197_6_a0,
     author = {V. G. Boltyanskii},
     title = {Separability axioms and a metric},
     journal = {Doklady Akademii Nauk},
     pages = {1239--1242},
     year = {1971},
     volume = {197},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_197_6_a0/}
}