Volume 59, Issue 137, April 2013, Pages 120-123
EMAN M.A. EL-NASER; GHADA A.E. MOHAMED; M.H. RATEB
Volume 57, Issue 129, April 2011, Pages 1-11
G.F. KHAMIS; EMAN M.A. EL-NASER; A.A. AAMER