COOPER, John Mesozoic stratigraphy of the Sierrita mountains, Pima County, Arizona / by John R. Cooper. -- Washington : United States Government Printing Office, 1971 - 42 p. -- (Geological Survey Professional Paper ; 658-D). Subjects--Topical Terms: ArizonaEstratigrafíaMesozoico Universal Decimal Class. No.: 551.76(791)