1. Bleek, D. Letter to Käthe Woldmann, 11 April 1927. La Rochelle, Newlands, Western Cape (1927). Kathe Woldmann Papers BC 210 (Box 4), Manuscripts and Archives Department, University of Cape Town Libraries.
2. Unconquered territory: Narrating the Caledon Valley
3. De Harde, L. 2019. “Elizabeth Goodall: A quiet contribution to rock art research in southern Africa”. University of the Witwatersrand. Unpublished PhD Thesis. Johannesburg: University of the Witwatersrand.