Habets, P. and Gaudenzi, M. (1999) “Existence and multiplicity of positive solutions for boundary value problems of 2d order ODE”, Topological Methods in Nonlinear Analysis, 14(1), pp. 131–150. Available at: https://apcz.umk.pl/TMNA/article/view/TMNA.1999.024 (Accessed: 25 April 2024).