- Index to Twyfelfontein - Links to several research projects and concerns in respect to the Twyfelfontein rock art.
- Rock Art of Twyfelfontein, Namibia - A Survey into the Relationship between Animal-Engravings and Cupules By Maarten van Hoek. Including the Site Report on Twyfelfontein by Sven Ouzman
- Southern African rock art - Rock art at Rice is an introduction to prehistoric and historic rock art with an emphasis on pictographs (paintings) and petroglyphs (engravings.
- The Pre-Historical Period - Summary of pre-historical period of Namibia with special emphasis on Rock Art by Klaus Dierks.
- Twyfelfontein Rock Art Photos - Photo gallery of Twyfelfontein rock engravings.
- Upside down Kudu - Photos and descriptions by Grant S. McCall.
