Não informado. (1919). Scientific Survey of Porto Rico and the Virgin Islands. New York Academy of Sciences.
Chicago-Zitierstil (17. Ausg.)Não informado. Scientific Survey of Porto Rico and the Virgin Islands. New York: New York Academy of Sciences, 1919.
MLA-Zitierstil (8. Ausg.)Não informado. Scientific Survey of Porto Rico and the Virgin Islands. New York Academy of Sciences, 1919.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.