1. Association AP (2000) Diagnostic and statistical manual of mental disorders, 4th, text revision edn. American Psychiatric Association, Washington, D.C.
2. Buchanan RW, Carpenter WT (2000) Schizophrenia: introduction and overview. In: Sadock BJ, Sadock VA (eds) Comprehensive textbook of psychiatry, vol 1. Lippincott, Williams, and Wilkins, Philadelphia, pp. 1096–1110
3. Fleischhacker W (2000) Negative symptoms in patients with schizophrenia with special reference to the primary versus secondary distinction. L’Encephale 26(1):12–14
4. Zanello A, Curtis L, Badan Ba M, Merlo MC (2009) Working memory impairments in first-episode psychosis and chronic schizophrenia. Psychiatry Res 165(1–2):10–18
5. Potkin SG, Turner JA, Brown GG, McCarthy G, Greve DN, Glover GH, Manoach DS, Belger A et al (2009) Working memory and DLPFC inefficiency in schizophrenia: the FBIRN study. Schizophr Bull 35(1):19–31