TY - JOUR T1 - 4 TT - 4 JF - jsci JO - jsci VL - 1368 IS - 3 UR - http://jsci.khu.ac.ir/article-1-1266-fa.html Y1 - 1989 SP - 0 EP - 0 KW - 4 N2 - 4 M3 ER -