Carl Friedrich Forster's Handbuch der Cacteenkunde in ihrem ganzen Umfange :nach dem gegenwartigen Stande der Wissenschaft bearbeitet und durch die seit 1846 begrundetet Gattungen und neu eingefuhrten Arten vermehrt - Förster, Carl Friedrich. (Wöller, 1886)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1903)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1906)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1908)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1909)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1910)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1911)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1914)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1915)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1919)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1920)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1922)