| title | ISBN-13 (ISBN-10) | year of publication | |
|---|---|---|---|
| Bioastronomy: The Search for Extraterrestrial Life, the Exploration Broadens: Proceedings | 978-0-387-54752-7 (0-387-54752-5) | 1991 | |
| Relativistic Cosmology. An Introduction | 978-3-540-10138-3 (3-540-10138-1) | 1980 |