@article{
  author = {Hermann, Martin, Saravi, Masoud, Ebrahimi Khah, Hadi},
  title = {Analytical study of nonlinear oscillatory systems using the Hamiltonian approach technique},
  journal = {Journal of Theoretical and Applied Physics},
  year = {2014},
  volume = {0},
  number = {3},
  pages = {0-0},
  doi = {10.1007/s40094-014-0133-9}
}