De Wilde, W. J., and B. Duyfjes. “The genus Canthium (Rubiaceae, Vanguerieae) in Thailand, with a note on the typification of the genus”. Thai Forest Bulletin (Botany), vol. 50, no. 2, Nov. 2022, pp. 161-80, doi:10.20531/tfb.2022.50.2.16.