@article{RSMUP_1958__28__107_0,
     author = {Frigerio, Alberto},
     title = {Sui quasi gruppi associati ai gruppi},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {107--111},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {28},
     year = {1958},
     mrnumber = {99375},
     zbl = {0082.24701},
     language = {it},
     url = {http://www.numdam.org/item/RSMUP_1958__28__107_0/}
}