Klingler, D. E., Johnson, J. H., Giannetti, R. A., & Williams, T. A. (1977). Comparison of the clinical utility of the MMPI basic scales and specific MMPI state-trait scales: A test of Dahlstrom’s hypothesis. Journal of Consulting and Clinical Psychology, 45(6), 1086–1092. American Psychological Assn, US,  http://www.apa.org