Reference link

Kaplan. E( 1996). Tundra. Tarrytown. NY: Benchmark Books 1-298.
Weigel, M. (2000). Encyclopedia of Biomes. M.I: 35-478.
Albert, W. (1972). The Life of the Far North. United States: McGraw-Hill, Inc.
"Wildlife Of the Arctic Tundra" Wildlife Explorer, Card 8, International Masters Publishers USA, 1998.