Volume 46.2, Issue 92, January 2002, Pages 84-106
H.M. Abd El-Hafeez; Samar S. Tawfik; M.A. Kandeil; A.N. Sayed
Volume 43.1, Issue 85, April 2000, Pages 51-74
H.M. Abd El-Hafeez; Samar S. Tawfik; Elham S.E. Saleh; Hanaa I. Faheem; S.Kh. Abd El-Ghaffar