BOERICKE, WILLIAM F. PLACERS GOLD SMALL OPERATING AND PROSPECTING - 2 - NEW YORK-U.S.A. JOHN WILEY & SONS 1936 - 145 pag 19 cm - 0 0 . GOLD PLACERS-OPERATING Subjects--Topical Terms: CIENCIAS PURAS Dewey Class. No.: 553.411 / B66