References
- Hartshorne , H. and May , M. A. 1928 . Studies in deceit: Book 1. General methods and results. Book 2. Statistical methods and results , xxi+414 New York : Macmillan . ix+306
- Thurstone , L. L. and Chave , E. K. 1929 . The measurement of attitude , 96 Chicago : Univ. Chicago Press .