References
- Sims A. Symptoms in the mind2nd edn. WB Saunders, London 1995
- Cutting J. Catatonia, definition and classification. Schizophrenia, SR Hirsch, DR Weinberger. Blackwell Science, Oxford 1995; 19–20
- Isaac M, Janca A, Sartorius N. ICD 10 Symptom glossary for mental disorders. Hogrefe & Huber, Geneva 1996