@article{
  author = {Goodarzi, Khodayar},
  title = {Integrating factor, first integral and λ-symmetry for vector ODEs of second orders},
  journal = {Theory of Approximation and Applications},
  year = {2024},
  volume = {18},
  issue = {2},
  pages = {1-6},
  doi = {},
  url = {https://sanad.iau.ir/fa/Article/909822}
}