@article{article536,
  title = {Fraud Risk Management for GSM Systems},
  author = {TÜFEKÇİOĞLU, O. and BİRİCİK, G. and DİRİ, B.},
  journal = {Sigma Journal of Engineering and Natural Sciences},
  year = {2017},
  volume = {8},
  pages = {169-174},
  doi = {}
}