| Entry | Volume | Pages |
|---|---|---|
| Zonneveld, B.J.M.: Jovibarba in France and Italy | 48 | 46 |
| Zonneveld, B.J.M.: Sempervivums in Bulgaria | 50 | 117 |
| Zonneveld, B.J.M.: Sempervivums in Karinthia and Styria | 49 | 83 |
| Zonneveld, B.J.M.: Sempervivums in Southern Yugoslavia | 49 | 322 |
| Zonneveld, B.J.M.: White-flowering and Other Colour Deviations of Sempervivum | 46 | 212 |