1. Ackery, P.R. and Vane-Wright, R.I. 1984. Milkweed Butterflies. British Museum (Natural History), London.
2. Collins, N.M. and Morris, M.G. 1985. Threatened Swallowtail Butterflies of the World. The IUCN Red Data Book. IUCN, Cambridge, UK and Gland, Switzerland, vii+401pp.+8pls.
3. Bibby, C.J., Crosby, M.J., Heath, M.F., Johnson, T.H., Long, A.J., Stattersfield, A.J. and Thirgood, S.J. 1992. Putting Biodiversity on the Map: global priorities for conservation. ICBP, Cambridge, UK.
4. East, R. (Ed.) 1988. Antelopes. Global survey and regional actions plans. Part 1. East and northeast Africa. IUCN, Gland.
5. East, R. (Ed.) 1989. Antelopes. Global survey and regional actions plans. Part 2. South and south-central Africa. IUCN, Gland.