Nega Tolla, Pravee Vijchulata, Pornsri Chairatanayuth, and Suwapong Swsdiphanich. 2006. “Comparative Performances of Holstein-Friesian Cows under Smallholder and Large Scale Farmers’ Management in Central Rift Valley, Ethiopia”. Agriculture and Natural Resources 40 (1). Bangkok, Thailand:58-68. https://li01.tci-thaijo.org/index.php/anres/article/view/243505.