Canthium glaucum Hiern
subsp. frangula (S. Moore) Bridson
var. frangula

Bridson, D.M. (1998). Rubiaceae, Part 2 Flora Zambesiaca 5(2) Pages 317 - 318. (Includes a picture).

Burrows, J.E., Burrows, S.M., Lötter, M.C. & Schmidt, E. (2018). Trees and Shrubs Mozambique Publishing Print Matters (Pty), Cape Town. Page 917. As Canthium glaucum frangula (Includes a picture).

Chapano, C. & Mamuto, M. (2003). Plants of the Chimanimani District National Herbarium and Botanic Garden, Zimbabwe Page 11.

Coates Palgrave, K. (revised and updated by Meg Coates Palgrave) (2002). Trees of Southern Africa 3rd edition. Struik, South Africa Pages 1088 - 1089.

Curtis, B.A. & Mannheimer, C.A. (2005). Tree Atlas of Namibia National Botanic Research Institute, Windhoek Page 620. as Canthium glaucum

Drummond, R.B. (1975). A list of trees, shrubs and woody climbers indigenous or naturalised in Rhodesia. Kirkia 10(1) Page 276. As Canthium frangula

Mapaura, A. & Timberlake, J. (eds) (2004). A checklist of Zimbabwean vascular plants Southern African Botanical Diversity Network Report No. 33 Sabonet, Pretoria and Harare Page 71.

Phiri, P.S.M. (2005). A Checklist of Zambian Vascular Plants Southern African Botanical Diversity Network Report No. 32 Page 87.

Setshogo, M.P. (2005). Preliminary checklist of the plants of Botswana. Sabonet Report no. 37. Sabonet, Pretoria and Gaborone Page 96.

Van Wyk, B. & Van Wyk, P. (1997). Field Guide to Trees of Southern Africa. Struik, South Africa Pages 260 - 261. (Includes a picture).

Van Wyk, B. & Van Wyk, P. (2013). Field Guide to Trees of Southern Africa (Second edition) Struik, South Africa Pages 306 - 307. (Includes a picture).