Tathaporn Maison, Hugo Volkaert, Unaroj Boonprakob, and Yingyong Paisooksantivatana. 2005. “Genetic Diversity of Andrographis paniculataWall. ex Nees as Revealed by Morphological Characters and Molecular Markers”. Agriculture and Natural Resources 39 (3). Bangkok, Thailand:388-99. https://li01.tci-thaijo.org/index.php/anres/article/view/243337.