@article{RSMUP_2006__115__99_0,
     author = {Schmidt, Roland},
     title = {On the {Occurrence} of the {Complete} {Graph} $K_5$ in the {Hasse} {Graph} of a {Finite} {Group}},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {99--124},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {115},
     year = {2006},
     mrnumber = {2245590},
     zbl = {1167.20314},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_2006__115__99_0/}
}