1. Recent Research on Obsidian from Iowa Archaeological Sites
2. Bastian, Tyler 1969The Hudsonpillar and Freeman Sites, North-Central Oklahoma. Archaeological Site Report14. Norman, OK: Okla-homa River Basin Survey Project.
3. Baugh, Timothy G. 1982Edwards I (34BK2): Southern Plains Adaptations in the Protohistoric Period. Studies in Oklahoma’s Past8. Norman, OK: Oklahoma Archaeological Survey.