@article{TM_2015_288_a14,
     author = {Imre B\'ar\'any and Ruy Fabila-Monroy and Birgit Vogtenhuber},
     title = {$(n,m)$-fold covers of spheres},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {224--229},
     publisher = {mathdoc},
     volume = {288},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TM_2015_288_a14/}
}