Report of the Psychology Committee of the National Research Councilby National Research Council (U.S.). Psychology Committee1919
A Study of Ability Grouping in the Elementary School in Terms of Variability of Achievementby Parl West1933
Validation of the Method of Ability Grouping Devised for 6A Pupils of the Minneapolis Schoolsby Herbert Frithjof Sorenson1924
A Study of Homogeneous Grouping in Terms of Individual Variations and the Teaching Problemby Marvin Yard Burr1931
The Grouping of Pupilsby National Society for the Study of Education. Committee on the Grouping of Pupils1936
A Study of Ability Grouping in the Elementary School in Terms of Variability of Achievement, the Teaching Problem, and Pupil Adjustmentby Parl West1933