Volume 57, Issue 130, July 2011, Pages 1-9
M.H.M. ELBASHIR; B.E. ABDEL-AZIZ; I.A. ISHAG
Volume 56, Issue 127, October 2010, Pages 1-5
SHADIA A. OMER; S.H. AHMED
Volume 36.1, Issue 71, October 1996, Pages 181-187
A.I. EL-AZAB; A.A. EL-MARIMI