References
- 1961 . Statistics of Education , 22 – 22 . H.M.S.O. . Supplement to Part 2
- Oliver , R.A.C. 1961 . Examinations and English Education , Edited by: Wiseman , Stephen . 130 – 130 . Manchester University Press .
- Heim , A.W. 1955 . AH4 Verbal and nonverbal test obtainable from the National Foundation for Educational Research in England and Wales, Slough, Bucks.