Não informado. (1970). Commerce today. U.S. Department of Commerce.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Commerce Today. Washington: U.S. Department of Commerce, 1970.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Commerce Today. U.S. Department of Commerce, 1970.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.