United States. Bureau of Economic Analysis. "Personal Income and Outlays: May 2018 : Historical Comparisons, BEA 18-32," Bureau of Economic Analysis (BEA) News Releases (June 29, 2018). https://fraser.stlouisfed.org/title/6148/item/602640/content/pdf/bea_newsreleases_20180629_historical-comparison, accessed on March 19, 2025.