Georgieva, Ivelina http://orcid.org/0000-0002-1381-5618
Kersten, Michael http://orcid.org/0000-0002-6385-7031
Tunega, Daniel http://orcid.org/0000-0003-0822-1580
Funding for this research was provided by:
German Research Foundation ((No. GE 1676/1))
Bulgarian National Science Fund (DH09/9/2016)
Article History
Received: 12 March 2020
Accepted: 2 July 2020
First Online: 17 July 2020