By Hanna, Paul Robert.
New York | London D. Appleton-Century 1936 .
xiv, 303 p. , "A publication of the Progressive education association." | Includes index. | Printing Master Micfilm 7020. | Master Negative SOL MN01069.05 VA@. 21 cm..

New York John Day Co. 1932 .
350 p. , Originally published as four special numbers of Progressive education, 1926, 1927, 1928 and 1931, respectively. The first number was also published as a separate with special t.-p.