BENZENATI, Lyna, and Karima MEBARKI. “An Extension of Krasnoselskii’s Cone Fixed Point Theorem for a Sum of Two Operators and Applications to Nonlinear Boundary Value Problems”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 68, no. 2, June 2023, pp. 423–438, doi:10.24193/subbmath.2023.2.16.