Wassie Haile, Thongchai Mala, Yongyuth Osotsapar, and Visoot Verasan. 2006. “Screening of Ethiopian Traditional Medicinal Herbs for their Nitrification Inhibiting Ability”. Agriculture and Natural Resources 40 (1). Bangkok, Thailand:74-82. https://li01.tci-thaijo.org/index.php/anres/article/view/243507.