@article{DMSMF_1989_1989_1_a0,
     author = {Piergallini, Ricardo},
     title = {Manifolds as branched covers of spheres.},
     journal = {Disertaciones del Seminario de Matem\'aticas Fundamentales},
     pages = {1-25},
     publisher = {mathdoc},
     volume = {2},
     year = {1989},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMSMF_1989_1989_1_a0/}
}