Godin, A. J. 1977. Wild mammals of New England. The Johns Hopkins University Press, Baltimore and London. Pp. 280-282.
Peek, J. M., D. E. Brown, S. R. Kellert, L. D. Mech, J. H. Shaw and V. V. Ballenberghe. 1991. Restoration of Wolves in North America. The Wildlife Society, Tech. Review 91-1, Bethesda, Maryland.
U. S. Fish and Wildlife Service. 1992. Recovery Plan for the Eastern Timber Wolf. Twin Cities, Minnesota. 73 pp.
http://www.okczoo.com/canid/gray-wolf.htm
http://www.nsrl.ttu.edu/tmot1/canilupu.htm
http://www.dfw.state.or.us/ODFWhtml/InfoCntrWild/gray_wolf/wolf_main.htm
