1. Green, R. G., Minn. Wildlife Dis. Invest., 2, 106 (1936).
2. Green, R. G., Minn. Wildlife Dis. Invest., 3, 83 (1937).
3. Green, R. G., Minn. Wildlife Dis. Invest., 3, 173 (1937).
4. Ender, F., and Helgebostad, A., Skand. Vet. Tidskr., 29, 1232 (1939).
5. Swale, F. S., Amer. Fur Breeder, 14, 20 (1941).