US BUMINES IC7990- MN DEPOSITS OFEASTERN ARIZONA,P 171-173.(DESCRIBES DEPOSIT & GIVES ANALYSIS USED IN MATRIX)USGS RAW MATERIAL COMPILATIONS - MANGANESE BY MAX CRITTENDEN(GIVES TONNAGE ESTIMATE P 16)SCHRADER F C 1915 USGS BULL 582 P.275USBM CORONADO NATIONAL FOREST STUDY