Manev, Mancho http://orcid.org/0000-0001-6181-8955
Tavkova, Veselina
Funding for this research was provided by:
Plovdiv University “Paisii Hilendarski” (MU19-FMI-020)
Plovdiv University “Paisii Hilendarski” (MU19-FMI-020)
Article History
Received: 12 June 2019
Revised: 12 June 2019
First Online: 5 August 2019