Bauer, Brian S.; Covey, R. Alan (2002). "Processes of State Formation in the Inca Heartland (Cuzco, Peru)". American Anthropologist. 104 (3): 846–64. doi:10.1525/aa.2002.104.3.846.
Alan Covey, R (2003). "A processual study of Inka state formation". Journal of Anthropological Archaeology. 22 (4): 333–57. doi:10.1016/S0278-4165(03)00030-8.