@article{
  author = {Hekmatnia, Mohsen, Amirteimoori, Alireza, Kordrostami, Sohrab, Vaez-Ghasemi, Mohsen},
  title = {Estimation of cost efficiency for firms in different technologies using data envelopment analysis},
  journal = {Journal of New Researches in Mathematics},
  year = {2020},
  volume = {6},
  number = {4},
  pages = {121-130},
  doi = {}
}