http://www.alarabiahconference.org/uploads/conference_research-1949421069-1463565290-2175.pdf

http://elwahat.univ-ghardaia.edu.dz/annonce/03/%D8%A7%D9%84%D8%B4%D8%B9%D8%B1%20%D8%A7%D9%84%D8%B4%D8%B9%D8%A8%D9%8A%20%D8%A7%D9%84%D8%AF%D9%8A%D9%86%D9%8A.pdf