Micheletti, Anna Maria, and Angela Pistoia. “A Note on the Resonance Set for a Semilinear Elliptic Equations and an Application to Jumping Nonlinearities”. Topological Methods in Nonlinear Analysis 6, no. 1 (September 1, 1995): 67–80. Accessed July 22, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.1995.032.