Iskrov, Georgi
Vasilev, Georgi
Mitev, Martin
Nikolova, Ralitsa
Stoykova, Mariya
Stefanov, Rumen
Article History
First Online: 14 August 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: Ethical approval was not required for this study in accordance with national and institutional guidelines. The survey was sociological from a methodological point of view, with no clinical research. No personal data were saved or analyzed.