Wang, Guotao, Zedong Yang, Ravi P. Agarwal, and Lihong Zhang. “Study on a Class of Schrödinger Elliptic System Involving a Nonlinear Operator”. Nonlinear Analysis: Modelling and Control 25, no. 5 (September 1, 2020): 846–859. Accessed July 22, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/18385.