@article{04061506, title = {On a variation of Sands' method.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {9}, year = {1986}, pages = {597-604}, doi = {10.1155/S0161171286000753}, zbl = {0651.20034}, language = {en}, url = {http://dml.mathdoc.fr/item/04061506} }
Obaid, Evelyn E. On a variation of Sands' method.. International Journal of Mathematics and Mathematical Sciences, Tome 9 (1986) pp. 597-604. doi : 10.1155/S0161171286000753. http://gdmltest.u-ga.fr/item/04061506/