@article{IVM_1972_9_a14,
     author = {A. M. Skryago},
     title = {On a~problem of {A.\,D.~Wallace} on the structure of semigroups on spheres},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {99--108},
     publisher = {mathdoc},
     number = {9},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1972_9_a14/}
}