Volume 28, Issue 2, December 2005, Pages 261-267
D. T. A. Youssef
Volume 24, Issue 2, December 2001, Pages 145-151
A. A. Khalifa; D. T. A. Youssef
Volume 22, Issue 2, December 1999, Pages 157-166
Azza A. Khalifa; D. T. Youssef