@article{PA20110018.pdf, <br>author="Sheila Coulson, Sigrid  Staurset, and Nick Walker",<br>title="Ritualized Behavior in the Middle Stone Age: Evidence from Rhino Cave, Tsodilo Hills, Botswana",<br>journal="PaleoAnthropology",<br>year="2011",<br>volume="2011",<br>pages="18-61"<br>}