Coti Zelati, V. and Rabinowitz, P. H. (2001) “Heteroclinic solutions between stationary points at different energy levels”, Topological Methods in Nonlinear Analysis, 17(1), pp. 1–21. Available at: https://apcz.umk.pl/TMNA/article/view/TMNA.2001.001 (Accessed: 27 April 2024).