References
Heÿl, C.W. 1978. ‘n Vraelys-ondersoek na probleemvoelskade in Kaapland. Unpublished research report (Birds). pp. 199-207. Department of Nature and Environmental Conservation, Cape Provincial Administration, Cape Town.
Heÿl, C.W. 1986. Cumatetralyl as an avicide for use against the Cape sparrow. South African Journal of Enology and Viticulture 7(2): 71-5.
Hockey, P.A.R., Dean, W.R.J. & P.G. Ryan (Eds). 2005. Roberts Birds of Southern Africa, 7th Edition. Trustees of the John Voelcker Bird Book Fund, Cape Town.
Swart, P.L. & Flight, I. 1982. Plaagvoels van sagtevrugte in Wes-Kaapland: oorsigtelike weergawe en waardeskatting. Unpublished report. Fruit and Fruit Technology Research Institute, Stellenbosch.