United States. Bureau of the Census. (1964). Providencia: A case study in economic censuses. s.n.
Cita Chicago (17th ed.)United States. Bureau of the Census. Providencia: A Case Study in Economic Censuses. [Washington: s.n, 1964.
Cita MLA (9th ed.)United States. Bureau of the Census. Providencia: A Case Study in Economic Censuses. s.n, 1964.
Atenció: Aquestes cites poden no estar 100% correctes.