@article{02161824, title = {Essential }, journal = {Journal of Applied Mathematics and Stochastic Analysis}, volume = {2004}, year = {2004}, pages = {1-8}, doi = {10.1155/S1048953304302017}, zbl = {1084.47044}, language = {en}, url = {http://dml.mathdoc.fr/item/02161824} }
Agarwal, R.P.; O'Regan, Donal. Essential . Journal of Applied Mathematics and Stochastic Analysis, Tome 2004 (2004) pp. 1-8. doi : 10.1155/S1048953304302017. http://gdmltest.u-ga.fr/item/02161824/