References
- Department of Agriculture . Annual Report for 1936–1937
- Montgomerie , R. F. , Bosworth , T. J. and Glover , R. E. 1938 . J. comp. Path. , 51 : 87 – 87 .
- Ramirez , A. M. , Gray , M. L. and Thorp , F. J. 1951 . Amer. J. vet. Res. , 12 : 201 – 201 .