@article{
  author = {Torabi, K, Afshari, H, Sadeghi, M, Toghian, H},
  title = {Exact Closed-Form Solution for Vibration Analysis of Truncated Conical and Tapered Beams Carrying Multiple Concentrated Masses},
  journal = {Journal of Solid Mechanics},
  year = {2017},
  volume = {9},
  number = {4},
  pages = {760-782},
  doi = {}
}