@article{PMIHES_1959__3__19_0,
     author = {Mazur, Barry},
     title = {On the structure of certain semi-groups of spherical knot classes},
     journal = {Publications Math\'ematiques de l'IH\'ES},
     pages = {19--27},
     publisher = {Institut des Hautes \'Etudes Scientifiques},
     volume = {3},
     year = {1959},
     mrnumber = {116347},
     zbl = {0119.38703},
     language = {en},
     url = {http://www.numdam.org/item/PMIHES_1959__3__19_0/}
}