Image Source for upper right and left: http://www.historyplace.com/unitedstates/childlabor/index.html
lower left: Freedman, Lewis.  Kids At Work:  Lewis Hine And The Crusade Against Child Labor,.  Photographs by Lewis Hine.  New York:    Books Clarion.  1945.  lower right: Parker, David L with Lee Engfer and Robert Conrow. Stolen Dreams.  Minneapolis:  Lerner Pub. Comp.  1998.