@article{
  author = {Rao, K. P. R., Kishore, G. V. N., Sadik, Sk.},
  title = {Unique common coupled fixed point theorem for four maps in $S_b$-metric spaces},
  journal = {Journal of Linear and Topological Algebra},
  year = {2017},
  volume = {6},
  number = {1},
  pages = {29-43},
  doi = {}
}