1. Ahlstrom, Karl-George. Studies in Spelling I: Analysis of Three Different Aspects of Spelling Ability. Uppsala, Sweden: Institute of Education, Uppsala University, 1964, Pp. 46. Factor analytic investigation of 14 criterion variables in relation to spelling and reading ability among 196 pupils in grade 4 in Uppsala, Sweden schools
2. Austin, Mary, and Morrison, Coleman. The First R: The Harvard Report on Reading in The Elementary Schools. New York: Macmillan, 1963. Pp, xi 4–269. A survey of the content and conduct of American reading instruction based upon questionnaire, interview and observational data gathered from 795 school systems in 1023 participating communities of 10, 000 or more population.