| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Plants of Angola =: Plantas de Angola | 978-1-919976-45-7 (1-919976-45-0) | 2008 | |
| The Aloe Names Book | 978-1-84246-419-9 (1-84246-419-1) | 2011 | Olwen M. Grace · Gideon F. Smith · Ronell R. Klopper |