Sisakhon, K., K. . Chayamarit, N. . Wongkantrakorn, D. Middleton, W. . Kiewbang, W. Salee, and S. . Vajrodaya. “The Genus Phyllocyclus (Gentianaceae) in Thailand”. Thai Forest Bulletin (Botany), vol. 49, no. 2, Sept. 2021, pp. 173-7, doi:10.20531/tfb.2021.49.2.03.