Zima, Mirosława, and Gabriela Szajnowska. “A Fixed Point Index Approach to a Third Order Nonlocal Boundary Value Problem”. Topological Methods in Nonlinear Analysis 65, no. 2 (June 14, 2025): 673–686. Accessed December 30, 2025. https://apcz.umk.pl/TMNA/article/view/62304.