@article{BagderinaTarkhanov2014,
  author    = {Bagderina, Yulia Yu. and Tarkhanov, Nikolai Nikolaevich},
  title     = {Differential invariants of a class of Lagrangian systems with two degrees of freedom},
  series = {Journal of mathematical analysis and applications},
  volume    = {410},
  journal   = {Journal of mathematical analysis and applications},
  number    = {2},
  publisher = {Elsevier},
  address   = {San Diego},
  issn      = {0022-247X},
  doi       = {10.1016/j.jmaa.2013.08.015},
  pages     = {733 -- 749},
  year      = {2014},
  language  = {en}
}