Graef, J. R., Heidarkhani, S. and Kong, L. (2013) “Infinitely many solutions for systems of multi-point boundary value problems using variational methods”, Topological Methods in Nonlinear Analysis, 42(1), pp. 105–118. Available at: https://apcz.umk.pl/TMNA/article/view/TMNA.2013.027 (Accessed: 2 December 2024).