FLETT, A.; LETLEY, P. Brother Otto Mäeder: an examination and evaluation of his work as a rock art recorder in South Africa. Southern African Humanities, [S. l.], v. 19, p. 103–21, 2007. Disponível em: https://sahumanities.org/index.php/sah/article/view/243. Acesso em: 23 may. 2024.