Staykov, Kalin V.
Popchev, Dimitar
Doneva, Daniela D.
Yazadjiev, Stoytcho S.
Funding for this research was provided by:
COST Actions (CA16214, CA16104)
COST Actions (CA15117)
Bulgarian National Science Fund (DM 18/4)
Baden-Württemberg Stiftung (Eliteprogramme for Postdocs)
European Social Fund, the Ministry of Science, Research and the Arts Baden-Württemberg
Sofia University (No 80-10-73/2018, No 3258/2017)
Article History
Received: 6 June 2018
Accepted: 12 July 2018
First Online: 20 July 2018