Volume 22.2, Issue 44, January 1990, Pages 128-135
M.A. YOUSEF; M.A. ABD EL-KADER; A.R. EL-SHEIKH; S.M. EL-MAGAWRY
Volume 20.2, Issue 40, September 1988, Pages 20-23
S.M. EL-MAGAWRY; LA. IBRAHIM; M.F. DOWIDAR; M.A. YOUSIF