References
- Ash , W. J. 1969 . “ Raising ducks ” . In Farmers Bulletin , 2215 Washington, DC : US Department of Agriculture .
- Hutt , F. B. 1952 . The Jansen Khaki Campbell ducks . Journal of Heredity , 43 : 277 – 281 .
- Warren , A. G. 1973 . Ducks and geese in the tropics . Poultry International , June : 42
- Colorado State University Experiment Station Scientific Series Paper No. 2469. 21/5—a 333