1. AdamsCD. 1963. Compositae. In: HepperFN, editor. Flora of West Tropical Africa. 2nd ed., London: Crown Agents. pp. 225–297.
2. BakerJG. 1882. Compositae III. Asteroideae et Inuloideae. In: MartiusCFP, editor. Flora Brasiliensis. Fleischer Lipsiae. Vol. 6, no. 3. pp. 1–134.
3. BeentjeHJ. 2002. Compositae (Part 2). Flora of Tropical East Africa. Rotterdam: Balkema.