United States. Department of Commerce. "U.S. International Trade in Goods and Services: December 2016, BEA 17-06, CB 17-17, FT-900 (16-12),"
United States Department of Commerce News
(February 7, 2017).
https://fraser.stlouisfed.org/title/6148/item/602477, accessed on June 12, 2026.