Contributions to economic geology (short papers and preliminary reports), 1919, Part I, Metals and nonmetals except fuels. Deposits of manganese ore in Costa Rica. Deposits of manganese ore near Boqueron River, Panama
Contributions to economic geology (short papers and preliminary reports), 1919, Part I, Metals and nonmetals except fuels. Deposits of manganese ore in Costa Rica. Deposits of manganese ore near Boqueron River, Panama