*Rowley, Gordon, D. Cactus Handbook 5: Pachypodium and Adenium (British Cactus and Succulent Society, (1983) 1999)*Rowley, Gordon.
* Rowley, Gordon, D. Cactus Handbook 5: Pachypodium and Adenium (British Cactus and Succulent Society, (1983) 1999)* Rowley, Gordon.