United States. Children's Bureau
, Klein, Armin, 1892-1954
and Thomas, Leah C. (Leah Coleman), 1893-.
Posture and Physical Fitness, Bureau Publication No. 205 ,
Washington, D.C:
Government Printing Office,
1931, https://fraser.stlouisfed.org/title/8481,
accessed on December 21, 2025.