Dorothy Hosler discuss the use of various forms of metal money in pre-Columbian America.
Dorothy Hosler, Heather Lechtman, and Olaf Holm, Axe-Monies and Their Relatives (Washington D.C.: Dumbarton Oaks Research Library and Collection, 1990)
This study reconsiders axe-monies in relation to their production and as a representative example of the maritime trade that disseminated metallurgical techniques from Ecuador and Peru to West Mexico.