@article{RSMUP_2011__125__81_0,
     author = {Cossey, John and Stonehewer, Stewart},
     title = {On the rarity of quasinormal subgroups},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {81--106},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {125},
     year = {2011},
     mrnumber = {2866121},
     zbl = {1250.20014},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_2011__125__81_0/}
}