@article{UZERU_2015_1_a1,
     author = {A. F. Beknazaryan},
     title = {On blowup of certain covering spaces},
     journal = {Proceedings of the Yerevan State University. Physical and mathematical sciences},
     pages = {8--11},
     year = {2015},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UZERU_2015_1_a1/}
}