Neznakomova, Margarita
Boteva, Silvena
Tzankov, Luben
Elhag, Mohamed http://orcid.org/0000-0001-9048-0084
Article History
Received: 27 January 2018
Accepted: 10 April 2018
First Online: 19 April 2018
Compliance with ethical standards
:
: On behalf of all the authors, the corresponding author states that there is no conflict of interest.