1. The zoogeographical distribution of Chironomidae (Insecta : Diptera)
2. R.J. Behnke (1992 ) Native Trout of Western North America . American Fisheries Society Monograph 6. American Fisheries Society, Bethesda, MD, 275 pp.
3. L.S. Berg (1950 ) Natural Regions of the U.S.S.R . Macmillan, New York, 432 pp. (translated from Russian).