@article{
  author = {Poorfattah, Elnaz, Jafari Shaerlar, Akbar},
  title = {Direct method for solving nonlinear two-dimensional Volterra-Fredholm integro-differential equations by block-pulse functions},
  journal = {International Journal of Information, Security and Systems Management},
  year = {2015},
  volume = {4},
  number = {1},
  pages = {418-423},
  doi = {}
}