United States. Children's Bureau , Jenss, Rachel M. (Rachel Marie), 1903-1993 and Souther, Susan Paige, 1896-. Methods of Assessing the Physical Fitness of Children, Bureau Publication No. 263 , Washington, D.C: Government Printing Office, 1940, https://fraser.stlouisfed.org/title/8537, accessed on January 6, 2026.