@article{
  author = {baihi nezhad, maryam, jadidi, naser},
  title = {In  the fourth   century  the two capital   cities  in the  World  of Islam i.e.Baghdad},
  journal = {Journal of History},
  year = {2012},
  volume = {8},
  number = {29},
  pages = {1-40},
  doi = {}
}