PARRAGA QUINTANILLA CLEVER CONSTRUCCION DEL TUNEL LA NEGRA REGION NOR-ORIENTAL BAGUA-AMAZONAS - 0 - CERRO DE PASCO-PERU UNDAC 1993 - 87 pag. 30 cm. - 0 0 . INSTALACION/CAPTACION/AGUA/ENERGIA ELECTRICA/LABORES/SUBTERR Subjects--Topical Terms: Minas Dewey Class. No.: 622.26 / P26