Candela, Anna Maria, Everaldo Souto de Medeiros, Giuliana Palmieri, and Kanishka Perera. “Weak Solutions of Quasilinear Elliptic Eystems via the Cohomological Index”. Topological Methods in Nonlinear Analysis 36, no. 1 (April 23, 2010): 1–18. Accessed April 23, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.2010.024.