Hirsch, Ulrich. "On Regular Homotopy of Branched Coverings of the Sphere.." Manuscripta mathematica 21 (1977): 293-306. <http://eudml.org/doc/154469>.
@article{Hirsch1977, author = {Hirsch, Ulrich}, journal = {Manuscripta mathematica}, keywords = {regular homotopy of branched covering maps; branched coverings of the 2- sphere and 3-sphere; inequivalent Heegaard splittings}, pages = {293-306}, title = {On Regular Homotopy of Branched Coverings of the Sphere.}, url = {http://eudml.org/doc/154469}, volume = {21}, year = {1977}, }
TY - JOUR AU - Hirsch, Ulrich TI - On Regular Homotopy of Branched Coverings of the Sphere. JO - Manuscripta mathematica PY - 1977 VL - 21 SP - 293 EP - 306 KW - regular homotopy of branched covering maps; branched coverings of the 2- sphere and 3-sphere; inequivalent Heegaard splittings UR - http://eudml.org/doc/154469 ER -