Bradshaw Foundation African Rock Art

Gabon: 
https://www.bradshawfoundation.com/central-africa/index.php
Namibia: 
https://www.bradshawfoundation.com/rockartnetwork/colloquium_2017.php
Niger: 
https://www.bradshawfoundation.com/africa/sahara.php
Tanzania: 
https://www.bradshawfoundation.com/tanzania/index.php