"Aspects of Child Life," Ginn, 1914.
"The Story of a Sand Pile."
Hetherington, Clark W.
"The Demonstration Play School of 1913," University of California
Bulletin, 1914.
Hill, Patty Smith and others
"Experimental Studies in Kindergarten Education," Teachers College
publications, 1915.
Johnson, George E.
"Education by Plays and Games," Ginn & Co., 1907.
Lee, Joseph
"Play for Home," Bulletin No. 102, Playground and Recreation
Association of America.
Read, Mary L.