Wangwasit, K., and P. Chantaranothai. “A New Combination in Hedyotis (Rubiaceae)”. Thai Forest Bulletin (Botany), no. 30, Dec. 2014, pp. 69-71, https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/24855.