Pt Tambang Timah-Belitung Gp

BUKU STATISTICK, P.T. TAMBANG TIMAH (PERSERO) 1980.INTERNATIONAL TIN COUNCIL, TIN PRODUCTION AND INVESTMENT,1979, LONDON, ENGLAND.E&MJ INTERNATIONAL DIRECTORY OF MINING, 1981-1982.SUJITONO, S. AND SIMATUPANG, M., REVIEW OF DISCOVERIES OFNEW TIN DEPOSITS IN INDONESIA, FIFTH WORLD CONFERENCE ONTIN, OCTOBER, 1981.SIMATUPANG, M., ET. AL., INDONESIA TIN RESOURCES ANDPOTENTIAL, FOURTH TECHNICAL CONFERENCE ON TIN, KUALALUMPUR, 1974.TIN INTERNATIONAL, AUGUST, 1982.