@article{MZ_1982__179_173166,
     author = {Robert B. Howlett and I. Martin Isaacs},
     title = {On {Groups} of {Central} {Type.}},
     journal = {Mathematische Zeitschrift},
     pages = {555--569},
     publisher = {mathdoc},
     volume = {179},
     year = {1982},
     zbl = {0511.20002},
     url = {http://geodesic.mathdoc.fr/item/MZ_1982__179_173166/}
}