| Reference | {Deposit:: ROA, C., 5/53 , CHROMITE IN THE PHILIPPINES: PHILIPPINES BUREAU OF MINES, INFO. CIRCULAR NO. 15 , P. 14}{Deposit:: SANTOS-YNIGO, L., ESGUERRA, F., 1961 , GEOLOGY OF NICKELIFEROUS LATERITES OF NONOC, SURIGAO PROVINCE, PHIL.: PHILIPPINES BUREAU OF MINES, SPECIAL PROJECTS SERIES, PUBLICATION NO. 18} |