@article{
  author = {Soltani, Tahereh, Gandomkar, Amir, Ataei, Hooshmand, Mofidi, Abbas},
  title = {A Statistical Study of Mashhad׳s Air Polluted Days},
  journal = {Journal of Geography and Environmental  Studies},
  year = {2016},
  volume = {5},
  number = {17},
  pages = {127-133},
  doi = {}
}