@article{ADM_2003_1_a8,
     author = {I. V. Protasov},
     title = {Uniform ball structures},
     journal = {Algebra and discrete mathematics},
     pages = {93--102},
     publisher = {mathdoc},
     number = {1},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ADM_2003_1_a8/}
}