BoichukО. A., ZhuravlevV. F., and SamoilenkoA. M. “Weakly Nonlinear Boundary-Value Problems for Operator Equations With Pulse Influence”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 2 (February 25, 1997): 272–288. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5004.