Volume 21.2, Issue 42, May 1989, Pages 172-176
Y. KHAMIS; A.A. KAMEL; A.S. SOLIMAN; M.F. MAHFOUZ; M. EL-S. EASA
Volume 18.2, Issue 36, May 1987, Pages 101-103
M. EL-S. EASA; M. FAISAL