1. Negative v positive schizophrenia: definition and validation;Andreasen;Arch. Gen. Psychiatry,1982
2. The Scale for the Assessment of Negative Symptoms (SANS);Andreasen,1983
3. The Scale for the Assessment of Positive Symptoms (SAPS);Andreasen,1984
4. Evaluation of positive and negative symptoms in schizophrenia;Andreasen;Psychiatr. Psychobiol.,1986
5. Comprehensive Assessment of Symptoms and History (CASH);Andreasen,1987