This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Helmersen. ru en Russian geologist academician Gregor von Helmersen author other versions Custom marker PDRusEmpire births deaths Alumni of the National Mineral Resources University Cartographers from Russia Knights of the Order of St Alexander Nevsky Members of the Russian Academy of Sciences Alumni