Satit Areerak, Viroch Impithukas, Chairerk Suwannarat, & Cholawuth La-ied. (1991). Effects of Land Preparation and Fertilization as Soil Management on Corn Yield Grown on Lopburi Soil Series. Agriculture and Natural Resources, 25(2), 191–199. retrieved from https://li01.tci-thaijo.org/index.php/anres/article/view/241965