TY - BOOK AU - Chang, K. C. PY - 1993 DA - 1993// TI - Infinite Dimensional Morse Theory and Multiple Solution Problems PB - Birkhäuser CY - Boston UR - https://doi.org/10.1007/978-1-4612-0385-8 DO - 10.1007/978-1-4612-0385-8 ID - Chang1993 ER - TY - JOUR AU - Jung, T. AU - Choi, Q. H. PY - 2009 DA - 2009// TI - On the number of the periodic solutions of the nonlinear Hamiltonian system JO - Nonlinear Anal. TMA VL - 71 UR - https://doi.org/10.1016/j.na.2009.01.095 DO - 10.1016/j.na.2009.01.095 ID - Jung2009 ER - TY - JOUR AU - Jung, T. AU - Choi, Q. H. PY - 2009 DA - 2009// TI - Periodic solutions for the nonlinear Hamiltonian systems JO - Korean J. Math VL - 17 ID - Jung2009 ER - TY - CHAP AU - Rabinowitz, P. H. PY - 1986 DA - 1986// TI - CBMS Regional Conf. Ser. Math. 65 BT - Minimax Methods in Critical Point Theory with Applications to Differential Equations PB - Am. Math. Soc. CY - Providence ID - Rabinowitz1986 ER -