1. Chassin M. How do we decide whether an investigation or procedure is appropriate? In: Hopkins A, editor. Appropriate investigation and treatment in clinical practice. London: Royal College of Physicians; 1989. p. 21–9.
2. Campbell SM, Braspenning J, Hutchinson A, Marshall MN. Research methods used in developing and applying quality indicators in primary care. BMJ. 2003;326(7393):816–9.
3. Mann T. Clinical guidelines : using clinical guidelines to improve patient care within the NHS. London: Department of Health; 1996.
4. Michelsen S, Kastanje M, Flachs EM, Søndergaard G, Biering-Sørensen S, Madsen M, AMN A. Evaluation of the preventive child consultations in general practice. Copenhagen: Danish National Board of health, Statens Institut for Folkesundhed, Syddansk Universitet; 2011.
5. Campbell SM, Ludt S, Van Lieshout J, Boffin N, Wensing M, Petek D, et al. Quality indicators for the prevention and management of cardiovascular disease in primary care in nine European countries. Eur J cardiovasc Prev Rehabil. 2008;15(5):509–15.