Le Quellec J.-L. 2011. — Provoking lactation by the insufflation technique as documented by the rock images of the Sahara. Anthropozoologica 46.1 : 65–125.
The Saharan rock art iconography shows that the first diffusion of cattle in Africa came with several milking techniques, which contradicts for this continent Sherratt's hypothesis which considered milking as a “secondary revolution” which would have allowed a better exploitation of animals in arid zones.