Alexander, S.; McLaughlin, J.D.; Verwoerd, Daniel Wynand(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1997)
Thirty-four species of gastrointestinal helminths were found in 25 Anas undulata, 21 Anas erythrorhyncha,
ten Anas capensis and seven Anas smithii collected at Barberspan, South Africa. Excluding
four new taxa, 11 new ...
