Não informado. (1919). Scientific Survey of Porto Rico and the Virgin Islands. New York Academy of Sciences.
Chicago (17e ed.) BronvermeldingNão informado. Scientific Survey of Porto Rico and the Virgin Islands. New York: New York Academy of Sciences, 1919.
MLA (8e ed.) BronvermeldingNão informado. Scientific Survey of Porto Rico and the Virgin Islands. New York Academy of Sciences, 1919.
Let op: Deze citaties zijn niet altijd 100% accuraat.