1. Hayward RS, Wilson MC, Tunis SR, Bass EB, Guyatt G (1995) Users’ guides to the medical literature. VIII. How to use clinical practice guidelines. A. Are the recommendations valid? The Evidence-Based Medicine Working Group. JAMA 274:570–574
2. The National Health and Medical Research Council of Australia (1999) A guide to the development, implementation, and evaluation of clinical practice guidelines. The National Health and Medical Research Council of Australia, Canberra, ACT
3. Browman GP (2001) Development and aftercare of clinical guidelines: the balance between rigor and pragmatism. JAMA 286:1509–1511
4. World Health Organization (2003) Guidelines for WHO guidelines. Global programme on evidence for health policy. World Health Organization, Geneva
5. Guyatt G, Vist G, Falck-Ytter Y, Kunz R, Magrini N, Schunemann H (2006) An emerging consensus on grading recommendations? Evid Based Med 11:2–4