Ha, Chung-Wei, and Chung-Cheng Kuo. “Nonselfadjoint Resonance Problems With Nonlinearities of Superlinear Growth”. Topological Methods in Nonlinear Analysis 5, no. 2 (June 1, 1995): 357–364. Accessed July 22, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.1995.025.