Weena Nilawonk. (2009) Estimating potassium supplying power of selected maize soils of Thailand /. Kasetsart University,:ม.ป.ท.Weena Nilawonk. 2009. Estimating potassium supplying power of selected maize soils of Thailand /. ม.ป.ท.:Kasetsart University,;Weena Nilawonk. Estimating potassium supplying power of selected maize soils of Thailand /. ม.ป.ท.:Kasetsart University, 2009. Print.