10. Thorne E. T.: Newsletter, Veterinary Group of the SSC/IUCN 3, 11, 1988.
11. Smith G. R.: Botulism in Waterfowl. W: Animal Disease in Relation Conservation. M. A. Edwards, U. McDonnell (wyd.). Academic Press, London, 1982, s. 57.
12. Smith G. R., Oliphant J. C., White W. R.: J. Hyg. Camb. 89, 507, 1982.