TY - RPRT TI - The application of geochemical, botanical, geophysical, and remote sensing mineral prospecting techniques to tropical areas state of the art and needed research AU - John Van N. Dorr AU - D.B. Hoover AU - Terry W. Offield AU - H.T. Shacklette PY - 1971 DO - 10.3133/ofr7190 UR - https://pubs.usgs.gov/publication/ofr7190 ID - ofr7190 ER -