@article{03977778,
title = {Perturbations of normally solvable nonlinear operators. I.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {8},
year = {1985},
pages = {241-246},
doi = {10.1155/S0161171285000266},
zbl = {0605.47056},
language = {en},
url = {http://dml.mathdoc.fr/item/03977778}
}
Ray, William O.; Walker, Anita M. Perturbations of normally solvable nonlinear operators. I.. International Journal of Mathematics and Mathematical Sciences, Tome 8 (1985) pp. 241-246. doi : 10.1155/S0161171285000266. http://gdmltest.u-ga.fr/item/03977778/