United States. Bureau of Labor Statistics. "Occupational Wage Survey: Allentown-Bethlehem-Easton, Pennsylvania-New Jersey, February 1964 : Bulletin of the United States Bureau of Labor Statistics, No. 1385-53," Occupational Wage Survey (1964). https://fraser.stlouisfed.org/title/4510/item/497874, accessed on January 21, 2025.