@article{1103043336, author = {Campbell, H. E.}, title = {On the Casimir operator.}, journal = {Pacific J. Math.}, volume = {7}, number = {4}, year = {1957}, pages = { 1325-1331}, language = {en}, url = {http://dml.mathdoc.fr/item/1103043336} }
Campbell, H. E. On the Casimir operator.. Pacific J. Math., Tome 7 (1957) no. 4, pp. 1325-1331. http://gdmltest.u-ga.fr/item/1103043336/