Author(s):
1. Kremena Ivanova, National Centre of Radiobiology and Radiation Protection, Bulgaria
2. Zdenka Stojanovska, Faculty of Medical Sciences, Goce Delčev University Stip, Macedonia
3. Bistra Kunovska, National Centre of Radiobiology and Radiation Protection, Bulgaria
4. Desislava Djuvnakova, National Centre of Radiobiology and Radiation Protection, Bulgaria
5. Jana Djounova, National Centre of Radiobiology and Radiation Protection, Bulgaria
6. Nina Chobanova, National Centre of Radiobiology and Radiation Protection, Bulgaria