| year of publication | ISBN | author(s) | title |
|---|---|---|---|
| 1969 | 978-0-9500507-0-6 | Succulent Plant Institute | A synonymy of the genus Gymnocalycium, 1845-1967 |
| 1970 | 978-0-9500507-1-3 | John W. Pilbeam | The First Fifty Haworthias |
| 1971 | 978-0-9500507-2-0 | James Alan Hart · T.C. Wrigley | Sedums: Some observations on the genus by a study group of the Succulent Plant Institute |
| 1973 | 978-0-9500507-3-7 | Gilbert Leighton-Boyce · James Iliff | Sub-genus Tephrocactus: A Historical Survey with Notes on Cultivation |
| 1985 | 978-0-9500507-5-1 | John Thomas Bates | Haworthia Drawings |