United States. Bureau of Economic Analysis. "U.S. International Trade in Goods and Services: April 2016 : Full Release, BEA 16-26, CB 16-97, FT-900 (16-04),"
Bureau of Economic Analysis (BEA) News Releases
(June 3, 2016).
https://fraser.stlouisfed.org/title/6148/item/602346/content/pdf/bea_newsreleases_20160603_a, accessed on June 19, 2025.