@article{
  author = {Fathali, Jafar, Jafari Rad, Nader, Rahimi Sherbaf, Sadegh},
  title = {Unweighted p-center problem on extended stars},
  journal = {Iranian Journal of Optimization},
  year = {2014},
  volume = {6},
  number = {2},
  pages = {737-744},
  doi = {}
}