1. Freshwater ecoregions of the world: a new map of biographic units for freshwater biodiversity conservation;Abell;BioScience,2008
2. Ecozones of Saskatchewan;Acton,1998
3. The Whooping Crane;Allen,1952
4. Armbruster, M.J., 1990. Characterization of Habitat Used by Whooping Cranes During Migration. US Fish Wildl. Serv. Biol. Rep. 90 (4), U.S. Fish and Wildlife Service, Washington, DC.
5. Drainage in the Red River Valley of the North;Augustadt,1955