@article{MZ_1965__90_170492, author = {James E. Roseblade}, title = {The permutability of orthogonal subnormal subgroups.}, journal = {Mathematische Zeitschrift}, pages = {365--372}, year = {1965}, volume = {90}, zbl = {0131.02203}, url = {http://geodesic.mathdoc.fr/item/MZ_1965__90_170492/} }