United States. Children's Bureau
, Klein, Armin, 1892-1954
and Thomas, Leah C. (Leah Coleman), 1893-.
Posture Exercises : A Handbook for Schools and for Teachers of Physical Education, Bureau Publication No. 165 ,
Washington, D.C:
Government Printing Office,
1926, https://fraser.stlouisfed.org/title/8445,
accessed on December 11, 2025.