Authors
Milena K. Saleva
Public Health Sciences Department, Faculty of Public Health, Medical University – Pleven
Silviya S. Aleksandrova-Yankulovska
Public Health Sciences Department, Faculty of Public Health, Medical University – Pleven
© 2022 Milena K. Saleva, Silviya S. Aleksandrova-Yankulovska, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.