Ivanov, Dimiter http://orcid.org/0000-0002-0677-6569
Utescher, Torsten
Djorgova, Nadejda
Bozukov, Vladimir
Ashraf, A. Rahman
Funding for this research was provided by:
Ministry of Science and Education of Bulgaria (D01- 230/06.12.2018)
Article History
Received: 2 April 2020
Revised: 22 July 2020
Accepted: 9 December 2020
First Online: 13 March 2021
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.