1. The effect of standardization on a χ2 approximation in factor analysis in factor analysis;Bartlett;Biometrika,1951
2. Assessing the Validity of the PHQ-9, HADS, BDI-II and QIDS-SR16 in Measuring of Depression in a UK Sample of Primary Care Patients With a Diagnosis of Depression;Cameron,2011
3. Coefficient alpha and the internal structure of tests;Cronbach;Psychometrika,1951
4. [Reliability and validity of the Visual Analogue Scale (VAS) (author’s transl)];Fähndrich;Pharmacopsychiatria,1982
5. Reliability, validity, and clinical application of the visual analogue mood scale;Folstein;Psychol. Med.,1973