TY - JOUR T1 - 8 TT - 8 JF - jsci JO - jsci VL - 1368 IS - 3 UR - http://jsci.khu.ac.ir/article-1-1270-en.html Y1 - 1989 SP - 0 EP - 0 KW - 8 N2 - 8 M3 ER -