www.nesasy.org/pdf/Dina_Zaid.pdf
www.najah.edu/thesis/2924786.pdf
uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/.../AMSEPT98.pdf
ser-bu.univ-alger.dz/thesenum/ALMAHMUDI_MOHAMED.pdf
www.najah.edu/thesis/2924786.pdf
uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/.../AMSEPT98.pdf
ser-bu.univ-alger.dz/thesenum/ALMAHMUDI_MOHAMED.pdf