@article{MZM_2012_92_1_a4,
     author = {A. A. Dovgoshey and D. V. Dordovskij},
     title = {An {Ultrametricity} {Condition} for {Pretangent} {Spaces}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {49--58},
     publisher = {mathdoc},
     volume = {92},
     number = {1},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2012_92_1_a4/}
}