Revalska, Miglena
Iantcheva, Anelia
Funding for this research was provided by:
National Science Fund at the Ministry of Education and Science of the Republic of Bulgaria (DM06/2)
Article History
Received: 7 November 2017
Accepted: 7 February 2018
First Online: 13 February 2018
Compliance with ethical standards
:
: The authors declare that they have no conflicts of interest.