INFANTE, Gennaro; PIETRAMALA, Paolamaria; ZIMA, Mirosława. Positive solutions for a class of nonlocal impulsive BVPs via fixed point index. Topological Methods in Nonlinear Analysis, [S. l.], v. 36, n. 2, p. 263–284, 2010. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2010.036. Acesso em: 8 jul. 2025.