^
Daniel, I. Randolph (27 April 1998). "Artifacts: Hammerstones". Hardaway Revisited: Early Archaic Settlement in the Southeast. Tuscaloosa, Alabama: University of Alabama Press. p. 115. ISBN9780817309008. Retrieved 14 November 2024. Cobbles identified as hammerstones are recognized by battering and extensive pitting present on ends, edges, or intermediate surfaces.
^Charles Joseph Singer, Richard Raper, Trevor Illtyd Williams, A History of Technology, 1954,
Clarendon Press
^Neelima Dahiya, Arts and Crafts in Northern India: From the Earliest Times to C. 200 B.C., 1986, D.K. Publishers