1. Bjerner, B. (1949). Acta physiol. scand., Suppl. 65.
2. Bjerner, B., and Swensson, A. (1953). Acta med. scand., Suppl. 278, p. 102.
3. Statens offentliga;Bjerner, B.; Swensson, A.; Holm, A.; Swensson, A.,1948
4. Browne, R. C. (1949). Occup. Psychol., 23, 121.
5. Freeman, G. L., and Hovland, C. I. (1934). Psychol. Bull., 31, 777.