Cita APA (7th ed.)

Hopewell, S., & Clarke, M. (2004). Impact of grey literature on systematic reviews of randomized trials.

Cita Chicago (17th ed.)

Hopewell, S., i M. Clarke. Impact of Grey Literature on Systematic Reviews of Randomized Trials. 2004.

Cita MLA (9th ed.)

Hopewell, S., i M. Clarke. Impact of Grey Literature on Systematic Reviews of Randomized Trials. 2004.

Atenció: Aquestes cites poden no estar 100% correctes.