References
- Clarke , ML , Harvey , DG and Humphreys , DJ . 1981 . Veterinary Toxicology , 2nd edition 181 – 182 . London : Bailliere Tindall, .
- Roy , B , Popay , I , Champion , P , James , T and Rahman , A . 1998 . An Illustrated Guide to Common Weeds of New Zealand , 115 – 115 . New Zealand Plant Protection Society .