References

1. Sackett D (1999). Guidelines and killer B’s. ACP J Club 131(1): A13-A14.
2. Centre for Evidence Based Medicine ,Universidad de Oxford. (Citado el 2 de junio de 2009 y disponible en http://ebm.mcmaster.ca)
3. Gordon H. Guyatt, Drummond Rennie et al (2007). Users’ Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice. American Medical Association Press, 597-600.