TY - JOUR AU - Françoise, J. P. AU - Ragnisco, O. TI - Matrix second-order differential equations and hamiltonian systems of quartic type JO - Annales de l'I.H.P. Physique théorique PY - 1989 DA - 1989/// SP - 369 EP - 375 VL - 50 IS - 3 PB - Gauthier-Villars UR - http://archive.numdam.org/item/AIHPA_1989__50_3_369_0/ UR - https://zbmath.org/?q=an%3A0695.58012 UR - https://www.ams.org/mathscinet-getitem?mr=1017970 LA - en ID - AIHPA_1989__50_3_369_0 ER -