Henry Perrine: The Agave Sisalana or Sisal Hemp. In: Tropical Plants. [To accompany bill H. R. No. 553.] In the the House of Representatives. Washington 1838, S. 16 (online).
jstor.org
Sterling Evans: Dependent Harvests: Grain Production on the American and Canadian Plains and the Double Dependency with Mexico, 1880-1950. In: Agricultural History. Band 80, Nummer 1, 2006, S. 40, JSTOR:3745103.
tropicos.org
Flora Mesoamericana. (online), Zugriff am 26. Juni 2008.
