1
Mawhin J. Topological degree and boundary value problems for nonlinear differential equations[C]., 1993: 74-142.
2
Haim Brezis. Periodic solutions of nonlinear vibrating strings and duality principles. 1983.
3
A Bahri · P L Lions. Morse index of some min-max critical points. I: application to multiplicity results. 1988.
4
Clapp M. Morse Indices at Mountain Pass Orbits of Symmetric Functionals[C]., 2002: 1-13.
5
Capietto A, Mawhin J, Zanolin F, et al. A Continuation Approach To Superlinear Periodic Boundary-value-problems[J]. Journal of Differential Equations, 1990, 88(2): 347-395.
6
Long Y M. Multiple solutions of perturbed superquadratic second order Hamiltonian systems[J]. Transactions of the American Mathematical Society, 1989, 311(2): 749-780.
7
Zhang Q, Liu C. Infinitely many homoclinic solutions for second order Hamiltonian systems[J]. Nonlinear Analysis-theory Methods \u0026 Applications, 2010, 72(2): 894-903.
8
Phillipe Bolle · Nassif Ghoussoub · Hossein Tehrani. The multiplicity of solutions in non-homogeneous boundary value problems. 2000.
9
Clifford Henry Taubes. A framework for Morse theory for the Yang-Mills functional. 1988.
10
Mawhin J. Topological degree and boundary value problems for nonlinear differential equations[C]., 1993: 74-142.