Authors
Y. Mitova
Department of Epidemiology, Medical University – Sofia, Bulgaria
V. Doycheva
Department of Epidemiology, Medical University – Sofia, Bulgaria
© 2021 S. Angelova, Y. Mitova, V. Doycheva, published by Sofia Medical University
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.