TY - JOUR AU - Guyatt, G. PY - 1991 DA - 1991// TI - Evidence-based medicine JO - ACP J Club (Ann Intern Med) VL - 114 ID - Guyatt1991 ER - TY - STD TI - Guyatt G et al (2008) Users’ guides to the medical literature: a manual for evidence-based clinical practice, preface page, 2nd edn. McGraw-Hill, New York. ISBN 978-0-07-159036-5; MHID 0-07-159036-6 ID - ref2 ER - TY - STD TI - http://www.gradeworkinggroup.org Accessed 30 July 2009 UR - http://www.gradeworkinggroup.org ID - ref3 ER -