Não informado. (2020). Press Bulletin. State of California, Department of Natural Resources, Division of Mines.
Chicago-referens (17:e uppl.)Não informado. Press Bulletin. San Francisco, Calif: State of California, Department of Natural Resources, Division of Mines, 2020.
MLA-referens (8:e uppl.)Não informado. Press Bulletin. State of California, Department of Natural Resources, Division of Mines, 2020.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.