@article{
  author = {farajzadeh, Mohammad, Sarmadi, Mohammad Reza },
  title = {Study and analysis of the nature, principles, extent, types and sources of epistemology},
  journal = {Theological – Doctrinal Research (Islamic Azad University-Saveh Branch)},
  year = {2019},
  volume = {9},
  number = {35},
  pages = {195-226},
  doi = {}
}