Roberts, Ralph Jackson 1911- creator Irving, Earl M. (Earl Montgomery) 1911- text bibliography dcu Washington, [D.C.] U.S. G.P.O. 1957 monographic eng

print

x, 205 p. : ill., maps (some col.) ; 24 cm. + 16 folded maps in case. by Ralph J. Roberts and Earl M. Irving ; With a section on manganese deposits of Panama, by Frank S. Simons. "Prepared under the auspices of the International Cooperation Administration, U.S. Dept. of State." Includes index. Bibliography: p. 195-198. Mines and mineral resources Central America QE75 .B9 no. 1034 553 gs 57000204 U.S. Geol. Survey Liby 790212 20260227111405.0 gs 57000204