@article{DA_2005_12_3_a5,
     author = {T. I. Fedoryaeva},
     title = {Variety of balls in metric spaces of trees},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {74--84},
     publisher = {mathdoc},
     volume = {12},
     number = {3},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_2005_12_3_a5/}
}