1. Lazarus RS, Folkman S: Stress, appraisal and coping. 1984, New York: Springer Publishing Company
2. Palmer S: Occupational Stress. The Health and Savety Practitioner. 1989, 7: 16-18.
3. Middleton H, Shaw I: Distinguishing mental illness in primary care. BMJ. 2000, 320: 1420-1421. 10.1136/bmj.320.7247.1420.
4. Burton C: Beyond somatisation: a review of the understanding and treatment of medically unexplained physical symptoms (MUPS). British Journal of General Practice. 2003, 53: 231-239.
5. OECD Economic Surveys: Netherlands: Reform of the sickness and disability benefit schemes. 2004