| Reference | {Deposit:: SEARS, J. D., 1919, DEPOSITS OF MANGANESE ORE IN COSTA RICA: U.S. GEOL. SURV. BULL. 710-C, P. 71-72.}{Deposit:: ROBERTS, R. J., 1944, MANGANESE DEPOSITS IN COSTA RICA: U.S. GEOL. SURV. BULL. 935-H, P. 403.}{Deposit:: U.S. GEOLOGICAL SURVEY, DIRECCION GENERAL DE GEOLOGIA, MINAS E HIDROCARBUROS, UNIVERSIDAD DE COSTA RICA, 1987, MINERAL RESOURCE ASSESSMENT OF THE REPUBLIC OF COSTA RICA: U.S. GEOLOGICAL SURVEY MISCELLANEOUS INVESTIGATION SERIES MAP I-1865, 75 P.}{Production:: ROBERTS (1944)} |