Volume 21.1, Issue 41, January 1989, Pages 20-28
A. EL-S. DOUGBAG
Volume 21.1, Issue 41, January 1989, Pages 29-34
A. EL-S. DOUGBAG; A.M. KASSEM
Volume 14.1, Issue 27, January 1985, Pages 1-7
A. HIFNY; A.M. KASSEM; A. EL-S. DOUGBAG; A.K. OSMAN; R.M. EL-BAKARY