Ian Sinclair, Phil Hockey, Peter Hayman, Norman Arlott: The larger illustrated guide to birds of southern Africa, s. 388. Struik, 2005. ISBN 978-1770072435. Kirja Googlen teoshaussa (viitattu 11.6.2009). (englanniksi)
BirdLife International: Nectarinia olivaceaIUCN Red List of Threatened Species. Version 2013.2. 2012. International Union for Conservation of Nature, IUCN, Iucnredlist.org. Viitattu 26.1.2014. (englanniksi)