BioStor
 | An Analysis of the Flora of Southern Africa: Its Characteristics, Relationships, and Orgins Peter Goldblati (1978) Annals of the Missouri Botanical Garden 65: 369-436 |
 | Chromosome numbers of South African Acanthaceae Thomas F Daniel, Kevin Balkwill and Mandy-Jane Balkwill (2000) Proceedings of the California Academy of Sciences 52: 143-158 |