1. Great Lakes Fishery Commission Annual Report 1968: 71 (1969).
2. SCI REV GEN FISH COM 1969 43
3. THESIS U MINNESOTA 1969
4. U.S. FISH AND WILDLIFE SERVICE SPECIAL SCIENTIFIC REPORT. FISHERIES 1950 55
5. U.S. FISH AND WILDLIFE SERVICE FISHERY LEAFLET 1970 630