1. Primary and secondary stuttering;Bluemel C. S.;Proceedings of the American Speech Correction Association,1932
2. The relation of repetitions in the speech of young children to certain measures of language maturity and situational factors: Part I;Davis Dorothy M;Journal of Speech Disorders,1939
3. Egland George 0. An analysis of repetition and prolongations in the speech of young children. State University of Iowa unpublished Master's thesis 1938.
4. Froschels Emil Beitrage zur Symptomatologie des Stotterns Monatschr f. Ohrenheilk 1921 5 .
5. The role of evaluation in stuttering behavior;Johnson W.;Journal of Speech Disorders,1938