@article{AFM_1969_421-450_a3,
     author = {Matti Honkapohja},
     title = {Degree and point-inverses of mappings on spheres},
     journal = {Annales Fennici Mathematici},
     publisher = {mathdoc},
     volume = {421-450},
     year = {1969},
     doi = {10.5186/aasfm.1969.447},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1969.447/}
}