1. Williams, P. G., Smith, M. W., The Frozen Earth, Cambridge: Cambridge University Press, 1989, 59–82.
2. Camill, P., Clark, G. S., Climate change disequilibrium of boreal permafrost peatlands caused by local processes, American Naturalist, 1998, 15(3): 207–222.
3. Cheng, D.G., Wang, S. L., On the zonation of high-altitude permafrost in China, Journal of Glaciology and Geocryology (in Chinese), 1982, 4(2): 1–17.
4. Cheng, D.G., Problems on zonation of high-altitude permafrost, Acta Geographica Sinica (in Chinese), 1984, 39(2): 185–193.
5. Cheng, G. D., Dramis, F., Distribution of mountain permafrost and climate, Permafrost and Periglacial Processes, 1992, 3(2): 83–91.