Smits, Krisjanis
Olsteins, Dags
Zolotarjovs, Aleksejs
Laganovska, Katrina
Millers, Donats
Ignatans, Reinis
Grabis, Janis
Article History
Received: 18 November 2016
Accepted: 7 February 2017
First Online: 13 March 2017
Competing interests
: The authors declare no competing financial interests.