Pornponggrungrueng, P., and P. Chantaranothai. “Pollen Morphology of the Tribe Inuleae (Compositae) in Thailand”. Thai Forest Bulletin (Botany), no. 30, Dec. 2014, pp. 116-23, https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/24859.