How to find assessment instruments, rating scales, measures, symptom questionnaires, psychological tests, etc.?

For example, I just read an excellent article: Galderisi S, Mucci A, Dollfus S, et al. EPA guidance on assessment of negative symptoms in schizophrenia. Eur Psychiatry. 2021;64(1):e23. EPA...

01 January 1970 7,011 7 View