RT - Journal Article T1 - Vol.6No.2 JF - jeg YR - 2013 JO - jeg VO - 6 IS - 2 UR - http://jeg.khu.ac.ir/article-1-407-en.html SP - 1 EP - 4 AB - LA eng UL http://jeg.khu.ac.ir/article-1-407-en.html M3 ER -