Nigusu, Kifle, and Tsegaw Fentie. 2012. “Prevalence and Causes of Selected Respiratory Infections in Indigenous Gumuz Sheep in Metema District, Northwest Ethiopia”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 5 (1): 14-20. https://www.gssrr.org/JournalOfBasicAndApplied/article/view/1292.