Outline of or based on a speech delivered for the occasion of the opening of the 1970 WorldCon in Heidelberg
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| December 1970 |
|
Intrige auf Chibbu | Moewig | Chapbook | 3|3.1 |
| December 1970 |
|
Die Insel der Wissenschaftler | Moewig | Novel | 3|3.1 |
| January 1971 |
|
Science Fiction Review, January 1971 | Richard E. Geis | MAGAZINE | 6 |