@article{01417986, title = {A simple characterization of commutative }, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {22}, year = {1999}, pages = {885-888}, doi = {10.1155/S0161171299228852}, zbl = {0966.46030}, language = {en}, url = {http://dml.mathdoc.fr/item/01417986} }
Saworotnow, Parfeny P. A simple characterization of commutative . International Journal of Mathematics and Mathematical Sciences, Tome 22 (1999) pp. 885-888. doi : 10.1155/S0161171299228852. http://gdmltest.u-ga.fr/item/01417986/