@article{Asgharzada_2019, title={Definition of Natural Languages Using Context-free Grammer: In Context of Dari Language}, volume={4}, url={https://www.cribfb.com/journal/index.php/aijssr/article/view/427}, DOI={10.46281/aijssr.v4i2.427}, number={2}, journal={American International Journal of Social Science Research}, author={Asgharzada, Mahmood}, year={2019}, month={Nov.}, pages={167-170} }