Volume 25.1, Issue 49, April 1991, Pages 15-32
M.K. EL-NAFFAR; I.M. ANWAR; M.S. EL-HAWARY; A.B. MAHMOUD; AMNA M. MOSTAFA
Volume 24.2, Issue 48, January 1991, Pages 76-87
M.K. EL-NAFFAR; I.M. ANWAR; A.B. MAHMOUD; M.S. EL-HAWARY; AMNA M. MOSTAFA
Volume 24.2, Issue 48, January 1991, Pages 88-100
M.K. EL-NAFFAR; I.M. ANWAR; A.B. MAHMOUD; M.S. EL-HAWARY; AMNA M. MOSTAFA