Werke:
- Classification and use of protected natural and cultural areas : A report prep. at the IUCN General Assembly at Banff, Canada, sept. 1972 and the 2. World Conference on National Parks at Grand Teton...
- A System for defining and classifying natural regions for purposes of conservation : A progress report
- Bedrohte Natur : der Mensch u. d. Biosphäre