Djebali, S., and K. Mebarki. “Systems of φ-Laplacian Three-Point Boundary-Value Problems on the Positive Half-Line”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 67, no. 12, Dec. 2015, pp. 1626-48, https://umj.imath.kiev.ua/index.php/umj/article/view/2096.