Enjoying our latest content?
Log in or create an account to continue
- Access the most recent journalism from Nature's award-winning team
- Explore the latest features & opinion covering groundbreaking research
or
Rights and permissions
About this article
Cite this article
FRIEDMAN, G. Karst. Nature 240, 277–278 (1972). https://doi.org/10.1038/240277b0
Issue date:
DOI: https://doi.org/10.1038/240277b0