↑Gibbs Russell, G. E., W. G. M. Welman, E. Retief, K. L. Immelman, G. Germishuizen, B. J. Pienaar, M. Van Wyk & A. Nicholas. 1987. List of species of southern African plants. Memoirs of the Botanical Survey of South Africa 2(1–2): 1–152(pt. 1), 1–270(pt. 2).
↑Hansen, H. V. (1985), A taxonomic revision of the genus Perdicium (Compositae -Mutisieae). Nordic Journal of Botany, 5: 543–546. doi: 10.1111/j.1756-1051.1985.tb01691.x
