@article{00874391, title = {On a result of Williamson.}, journal = {Portugaliae Mathematica. Nova S\'erie}, volume = {53}, year = {1996}, pages = {35-41}, zbl = {0845.15013}, language = {en}, url = {http://dml.mathdoc.fr/item/00874391} }
Gong, Ming-Peng. On a result of Williamson.. Portugaliae Mathematica. Nova Série, Tome 53 (1996) pp. 35-41. http://gdmltest.u-ga.fr/item/00874391/