Adhikary, B. H., Vangnai, S., Attanandana, T., Swatdee, P., & Sripichitt, P. (1997). Growth and Nitrogen Production Rates of Azolla ( Azolla microphylla ) as Affected by Its Cultivation Methods : An Economic Perspective in Rice Cultivation in Thailand. Agriculture and Natural Resources, 31(1), 134–140. retrieved from https://li01.tci-thaijo.org/index.php/anres/article/view/240797