R.L. Spaulding, Achievement, creativity, and self-concept correlates of teacher-pupil transactions in elementary schools, Cooperative Research Project No. 1352, D.H.E.W. Office of Education, Washington, D.C., 1963. Siehe auch: Philip Jackson and Henriette Lahaderne, „Inequalities of teacher-pupil contact", in: PSYCHOLOGY IN THE SCHOOLS, 4 (1967), 204-211