Hechaichi, Hadjer, and Mircea Sofonea. “Analysis and Control of a Nonlinear Boundary Value Problem”. Nonlinear Analysis: Modelling and Control 22, no. 6 (October 27, 2017): 841–860. Accessed July 17, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/13365.