The Cactaceae : descriptions and illustrations of plants of the cactus family - Britton, Nathaniel Lord, 1859 -1934 (Carnegie Institution of Washington, 1923)

Las Cactáceas de MÉXICO - Bravo-Hollis, Helia, 1901 -2001 (UNAM [Imprenta universitaria], 1937)

Carnegie Institution of Washington publication - Carnegie Institution of Washington (Carnegie Institution of Washington, 1923)

Just's Botanischer Jahresbericht - Just, Johann Leopold, 1841 -1891 (Gebruder Borntraeger, 1925)