@article{SM_1989_63_1_a1,
     author = {V. A. Popov},
     title = {Extendability of local isometry groups},
     journal = {Sbornik. Mathematics},
     pages = {11--21},
     year = {1989},
     volume = {63},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1989_63_1_a1/}
}