Manev, Mancho http://orcid.org/0000-0001-6181-8955
Funding for this research was provided by:
Plovdiv University “Paisii Hilendarski” (MU19-FMI-020, FP19-FMI-002)
Article History
Received: 31 August 2019
Revised: 16 March 2020
Accepted: 2 August 2020
First Online: 20 August 2020