The Extracting of Germanium from Crude Oxide
<p>Since the discovery of germanium in certain American zinc ores, notably that of Joplin, Mo., several procedures have been suggested for the extraction of the germanium. These procedures, however, were simple distillations of the zinc ore with hydrochloric acid carried out in the laboratory...
Internet
https://thesis.library.caltech.edu/482/1/Clarke_ps_1921.pdfClarke, Philip Seymour (1921) The Extracting of Germanium from Crude Oxide. Bachelor's thesis, California Institute of Technology. doi:10.7907/XZ1Y-JE25. https://resolver.caltech.edu/CaltechETD:etd-02032005-111330 <https://resolver.caltech.edu/CaltechETD:etd-02032005-111330>