1. E. A. El-Sawi:
Department of Chemistry, University College for Women, Ain Shams University Heliopolis, Cairo, Egypt
2. T. B. Mostafa:
Department of Chemistry, University College for Women, Ain Shams University Heliopolis, Cairo, Egypt
3. I. K. H. El-Sayed:
Department of Chemistry, University College for Women, Ain Shams University Heliopolis, Cairo, Egypt