@article{MZ_1960__73_169837,
     author = {Trueman MacHenry},
     title = {The tensor product and the 2nd nilpotent product of groups.},
     journal = {Mathematische Zeitschrift},
     pages = {134--145},
     year = {1960},
     volume = {73},
     zbl = {0121.27002},
     url = {http://geodesic.mathdoc.fr/item/MZ_1960__73_169837/}
}