Khelifi, Fathi. “Infinitely Homoclinic Solutions in Discrete Hamiltonian Systems Without Coercive Conditions”. J. Numer. Anal. Approx. Theory 49, no. 1 (September 8, 2020): 66–75. Accessed May 6, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1204.