{"id":"000832089","type":"book","title":"A chemical and mineralogical examination of the ceramic sequence from Tikal, el Peten, Guatemala","publisher":"Laboratory","publisher-place":"New Haven, Conn","container-title":"American journal of science, 267.1969, April: S. 465-477","author":[{"family":"Cowgill","given":"Ursula M."}],"issued":{"raw":"1969"}}