2016 Mekdes K. Gebremariam et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International Lic
ense (http://
creativecommons.org/licenses/by/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transfo
rm, and build upon the material for any purpose, even
commercially, provided the original work is properly cited and states its license
Med mindre annet er angitt, så er denne innførselen lisensiert som 2016 Mekdes K. Gebremariam et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International Lic ense (http:// creativecommons.org/licenses/by/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transfo rm, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license