@article{CMH_1975__50_139635,
     author = {Guido Mislin and Peter Hilton},
     title = {Bicartesian {Squares} of {Nilpotent} {Groups.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {477--492},
     publisher = {mathdoc},
     volume = {50},
     year = {1975},
     zbl = {0325.20031},
     url = {http://geodesic.mathdoc.fr/item/CMH_1975__50_139635/}
}