Li, Gongbao, and Chunhua Wang. “The Existence of a Nontrivial Solution to a Nonlinear Elliptic Problem of Linking Type Without the Ambrosetti-Rabinowitz Condition”. Annales Fennici Mathematici 36, no. 2 (August 1, 2011): 461–480. Accessed May 2, 2024. https://afm.journal.fi/article/view/135360.