1. Koopman, A., Porter, R., and Turner, N. (2020). Birds of KwaZulu-Natal and their Zulu Names. The John Voelcker Bird Book Fund. Cape Town, South Africa.
2. An additional List of Birds received from Natal.
3. Catalogue of African birds in the collection of R.B. Sharpe.
4. de Swardt, D. H. (2019). Going ... going ... Gurney’s. In search of South Africa's northernmost sugarbirds. The Lark 26:4–9.
5. de Swardt, D. H., and D. Engelbrecht (2019). Gurney’s Sugarbird - Ringing in the Hwiti Mountain region. The Lark 21:26–31.