@article{01883743, title = {Properness and topological degree for general elliptic operators.}, journal = {Abstract and Applied Analysis}, volume = {2003}, year = {2003}, pages = {129-181}, doi = {10.1155/S1085337503204073}, zbl = {1030.35038}, language = {en}, url = {http://dml.mathdoc.fr/item/01883743} }
Volpert, V.; Volpert, A. Properness and topological degree for general elliptic operators.. Abstract and Applied Analysis, Tome 2003 (2003) pp. 129-181. doi : 10.1155/S1085337503204073. http://gdmltest.u-ga.fr/item/01883743/