1. Systematic reviews;Chalmers,1995
2. Systematic reviews: critical links in the great chain of evidence;Mulrow,1998
3. Checklist for review articles;Oxman;BMJ,1994
4. Meta-analysis of randomized controlled trials;Sacks;N Engl J Med,1987
5. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews;Shea;BMC Med Res Methodol,2007