Infante G, Pietramala P, Zima M. Positive solutions for a class of nonlocal impulsive BVPs via fixed point index. TMNA [Internet]. 2010 Apr. 23 [cited 2024 Jul. 22];36(2):263-84. Available from: https://apcz.umk.pl/TMNA/article/view/TMNA.2010.036