1. Department of Pharmaceutical Sciences Faculty of Pharmacy, Medical University-Plovdiv, 4002 Plovdiv , Bulgaria
2. High-technological Center of Emergency Medicine, Plovdiv , Bulgaria
3. Department of Chemistry, Faculty of Pharmacy, Medical University Sofia 1000 Sofia , Bulgaria
4. Department of Statistics, Dokuz Eylul University, 35160 Izmir , Turkey
5. Chemistry Department, The Hashemite University, P. O. Box 150459 Zarqa 13115 Jordan
6. Laboratory of Chemometrics and Environmetrics, Faculty of Chemistry and Pharmacy, Sofia University “St. Kliment Ohridski”, 1164 Sofia , Bulgaria