RT - Journal Article T1 - Article - 8 JF - USWR YR - 2012 JO - USWR VO - 1 IS - 1 UR - http://ptj.uswr.ac.ir/article-1-31-en.html SP - 56 EP - 63 AB - LA eng UL http://ptj.uswr.ac.ir/article-1-31-en.html M3 ER -