5.9  References

Cooper 1984  
Cooper HM. The problem formulation stage. In: Cooper HM (editors). Integrating Research: a Guide for Literature Reviews. Newbury Park (CA): Sage Publications, 1984.

Counsell 1997  
Counsell C. Formulating questions and locating primary studies for inclusion in systematic reviews. Annals of Internal Medicine 1997; 127: 380-387.

Gøtzsche 2007  
Gøtzsche PC, Hróbjartsson A, Maric K, Tendal B. Data extraction errors in meta-analyses that use standardized mean differences. JAMA 2007; 298: 430-437.

Hedges 1994  
Hedges LV. Statistical considerations. In: Cooper H, Hedges LV (editors). The Handbook of Research Synthesis. New York (NY): Russell Sage Foundation, 1994.

Jackson 1980  
Jackson GB. Methods for integrative reviews. Review of Educational Research 1980; 50: 438-460.

Khan 2001  
Khan KS, ter Riet G, Glanville J, Sowden AJ, Kleijnen J (editors). Undertaking Systematic Reviews of Research on Effectiveness: CRD's Guidance for those Carrying Out or Commissioning Reviews (CRD Report Number 4) (2nd edition). York (UK): NHS Centre for Reviews and Dissemination, University of York, 2001.

Richardson 1995  
Richardson WS, Wilson MS, Nishikawa J, Hayward RSA. The well-built clinical question: a key to evidence based decisions. ACP Journal Club 1995: A12-A13.