1. Germanium and germanium compounds;Adams,1994
2. Los yacimientos minerales y de hidrocarburos de Bolivia;Ahlfeld,1964
3. Ore depositional processes in the Navan Zn–Pb deposit, Ireland;Anderson;Economic Geology,1998
4. Geochemistry of germanium in the metallic sulphide ore deposits in Japan;Ando,1964
5. Mineralizations of the Irish Midlands;Andrew,1993