Zewdie Wondatir. “Study on the Occurrence of External and Gastrointestinal Parasites and Sub-Clinical Mastitis on Crossbred Dairy Cows under Different Feeding and Management Conditions in the Central Highlands of Ethiopia”. Global Journal of Science Frontier Research, vol. 14, no. D7, May 2014, pp. 37-40, https://journalofscience.org/index.php/GJSFR/article/view/1394.