@article{01930008, title = {Closed orbits of }, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {2003}, year = {2003}, pages = {1047-1053}, doi = {10.1155/S0161171203208164}, zbl = {1016.37012}, language = {en}, url = {http://dml.mathdoc.fr/item/01930008} }
Noorani, Mohd.Salmi Md. Closed orbits of . International Journal of Mathematics and Mathematical Sciences, Tome 2003 (2003) pp. 1047-1053. doi : 10.1155/S0161171203208164. http://gdmltest.u-ga.fr/item/01930008/