• De Groote, S. L. (2000) PubMed, Internet Grateful Med, and Ovid: a comparison of three MEDLINE Internet interfaces. Medical Reference Services Quarterly 19, 113.
  • Delaney, A., Bagshaw, S. M., Ferland, A., Laupland, K., Manns, B. & Doig, C. (2007) The quality of reports of critical care meta-analyses in the Cochrane Database of Systematic Reviews: an independent appraisal. Critical Care Medicine 35, 589594.
  • Easterbrook, P. J., Berlin, J. A., Gopalan, R. & Matthews, D. R. (1991) Publication bias in clinical research. Lancet 337, 867872.
  • Flores-Mir, C., Major, M. P. & Major, P. W. (2006) Search and selection methodology of systematic reviews in orthodontics (2000–2004). American Journal of Orthodontics and Dentofacial Orthopedics 130, 214217.
  • Greenhalgh, T. & Peacock, R. (2005) Effectiveness and efficiency of search methods in systematic reviews of complex evidence: audit of primary sources. British Medical Journal 331, 10641065.
  • Haynes, R. B., McKibbon, K. A., Wilczynski, N. L., Walter, S. D., Were, S. R. & Team, H. (2005) Optimal search strategies for retrieving scientifically strong studies of treatment from Medline: analytical survey. British Medical Journal 330, 1179.
  • Haynes, R. B., Wilczynski, N., McKibbon, K. A., Walker, C. J. & Sinclair, J. C. (1994) Developing optimal search strategies for detecting clinically sound studies in MEDLINE. Journal of the American Medical Informatics Association 1, 447458.
  • Hopewell, S., Loudon, K., Clarke, M.J., Oxman, A.D. & Dickersin, K. (2009) Publication bias in clinical trials due to statistical significance or direction of trial results. Cochrane Database of Systematic Reviews, 1, MR000006.
  • Hopewell, S., McDonald, S., Clarke, M. & Egger, M. (2007) Grey literature in meta-analyses of randomized trials of health care interventions. Cochrane Database of Systematic Reviews 2, MR000010.
  • Jadad, A. R., Cook, D. J., Jones, A., Klassen, T. P., Tugwell, P., Moher, M. & Moher, D. (1998) Methodology and reports of systematic reviews and meta-analyses: a comparison of Cochrane reviews with articles published in paper-based journals. Journal of the American Medical Association 280, 278280.
  • Faggion, C.M. Jr, Liu, J., Huda, F. & Atieh, M. (2013) Quality of reporting in abstracts of systematic reviews with meta-analyses in Periodontology and Implant Dentistry. Journal of Periodontal Research doi: 10.1111/jre.12092.
  • Jüni, P., Holenstein, F., Sterne, J., Bartlett, C. & Egger, M. (2002) Direction and impact of language bias in meta-analyses of controlled trials: empirical study. International Journal of Epidemiology 31, 115123.
  • Kanaan, Z., Galandiuk, S., Abby, M., Shannon, K. V., Dajani, D., Hicks, N. & Rai, S. N. (2011) The value of lesser-impact-factor surgical journals as a source of negative and inconclusive outcomes reporting. Annals of Surgery 253, 619623.
  • Lefebvre, C., Manheimer, E. & Glanville, J. (2011) Chapter 6: searching for studies. In: Higgins JPT, Green S (eds). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011), The Cochrane Collaboration: Available from Accessed at 01 March 2013
  • Major, M. P., Major, P. W. & Flores-Mir, C. (2006) An evaluation of search and selection methods used in dental systematic reviews published in English. Journal of the American Dental Association 137, 12521257.
  • Montori, V. M., Wilczynski, N. L., Morgan, D., Haynes, R. B. & Team, Hedges (2005) Optimal search strategies for retrieving systematic reviews from Medline: analytical survey. British Medical Journal 330, 68.
  • Morrison, A., Polisena, J., Husereau, D., Moulton, K., Clark, M., Fiander, M., Mierzwinski-Urban, M., Clifford, T., Hutton, B. & Rabb, D. (2012) The effect of English-language restriction on systematic review-based meta-analyses: a systematic review of empirical studies. International Journal of Technology Assessment in Health Care 28, 138144.
  • Pham, B., Klassen, T. P., Lawson, M. L. & Moher, D. (2005) Language of publication restrictions in systematic reviews gave different results depending on whether the intervention was conventional or complementary. Journal of Clinical Epidemiology 58, 769776.
  • Pittler, M. H., Abbot, N. C., Harkness, E. F. & Ernst, E. (2000) Location bias in controlled clinical trials of complementary/alternative therapies. Journal of Clinical Epidemiology 53, 485489.
  • Relevo, R. & Balshem, H. (2011) Finding evidence for comparing medical interventions. In: Methods Guide for Effectiveness and Comparative Effectiveness Reviews [Internet]. Rockville, MD: Agency for Healthcare Research and Quality (US); 2008. Available at: (accessed on 15 February 2013).
  • Robinson, K. A. & Dickersin, K. (2002) Development of a highly sensitive search strategy for the retrieval of reports of controlled trials using PubMed. International Journal of Epidemiology 31, 150153.
  • Saha, S., Saint, S. & Christakis, D. A. (2003) Impact factor: a valid measure of journal quality? Journal of Medical Library Association 91, 4246.
  • Shea, B. J., Grimshaw, J. M., Wells, G. A., Boers, M., Andersson, N., Hamel, C., Porter, A. C., Tugwell, P., Moher, D. & Bouter, L. M. (2007) Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 7, 10.
  • Smith, V., Devane, D., Begley, C. M. & Clarke, M. (2011) Methodology in conducting a systematic review of systematic reviews of healthcare interventions. BMC Medical Research Methodology 11, 15.
  • Sterne, J.A.C., Egger, M. & Moher, D. (2011) Chapter 10: addressing reporting biases. In: Higginsa, JPT & Green, S (eds). Cochrane Handbook for Systematic Reviews of Intervention. Version 5.1.0 (updated March 2011). The Cochrane Collaboration, Available from Accessed at 01 March 2013.
  • Wong, S. S., Wilczynski, N. L. & Haynes, R. B. (2006) Developing optimal search strategies for detecting clinically sound treatment studies in EMBASE. Journal of the Medical Library Association 94, 4147.
  • Yoshii, A., Plaut, D. A., McGraw, K. A., Anderson, M. J. & Wellik, K. E. (2009) Analysis of the reporting of search strategies in Cochrane systematic reviews. KE. Journal of the Medical Library Association 97, 2129.