Baissa, T., Suwanarit, A., Osotsapar, Y. and Sarobol, E. (2007) “Status of Mn, Fe, Cu, Zn, B and Mo in Rift Valley Soils of Ethiopia: Laboratory Assessment”, Agriculture and Natural Resources. Bangkok, Thailand, 41(1), pp. 84–95. available at: https://li01.tci-thaijo.org/index.php/anres/article/view/244183 (accessed: 27 August 2026).