Hopewell, S., & Clarke, M. (2004). Impact of grey literature on systematic reviews of randomized trials.
芝加哥风格引文Hopewell, S., 与 M. Clarke. Impact of Grey Literature on Systematic Reviews of Randomized Trials. 2004.
MLA引文Hopewell, S., 与 M. Clarke. Impact of Grey Literature on Systematic Reviews of Randomized Trials. 2004.
警告：这些引文格式不一定是100％准确.