@article{Barillon_Volpert_1999, title={Topological degree for a class of elliptic operators in ${\mathbb R}^n$}, volume={14}, url={https://apcz.umk.pl/TMNA/article/view/TMNA.1999.034}, abstractNote={A class of elliptic operators in ${\mathbb R}^n$ is considered. It is proved that the operators are Fredholm and proper. The topological degree is constructed. Existence of solutions for a reaction-diffusion system is studied.}, number={2}, journal={Topological Methods in Nonlinear Analysis}, author={Barillon, Cristelle and Volpert, Vitaly A.}, year={1999}, month={Dec.}, pages={275–293} }