Glossary of "Biogeography (9th ed.)" by Cox et al. (2016)
- Ice that forms in the ground by freezing and pushing up soil.
- Cox, C. B., Moore, P. D. & Ladle, R. J. 2016. Biogeography: An Ecological and Evolutionary Approach, 9th ed. - xiii + 482 pp. Wiley Blackwell, Chichester.