I.: Newman, Kenneth: Newman’s Birds of Southern Africa. Johannesburg, Macmillan South Africa 1983. Pbk. ISBN 0869541706 / II.: Prozesky, O.P.M.: AField Guide to the Birds of Southern Africa. London, Collins 1974. Publ. clothbound w. dj. ISBN 0002120267 / III.: McLachlan, G. R. ; Liversidge, R. (Revised): Roberts Birds of Sout Africa. [Cape Town], Voelker Bird Book Fund 1975. Hardback. ISBN 0620005750.