中国科学院数学与系统科学研究院期刊网
Dual Morse Index for Subquadratic Hamiltonian Systems and the Stability of the Closed Characteristics
Chun Gen LIU
Acta Mathematica Sinica, Chinese Series . 2001, (6): 1073 -108 .  DOI: 10.12386/A2001sxxb0135