Context: Grey Literature (GL) recently has grown in Software Engineering (SE) research since the increased use of online communication channels by software engineers. However, there is still a limited understanding of how SE research is taking advantage of GL. Objective: This research aimed to understand how SE researchers use GL in their secondary studies. Method: We conducted a tertiary study of studies published between 2011 and 2018 in high-quality software engineering conferences and journals. We then applied qualitative and quantitative analysis to investigate 446 potential studies. Results: From the 446 selected studies, 126 studies cited GL but only 95 of those used GL to answer a specific research question representing almost 21% of all the 446 secondary studies. Interestingly, we identified that few studies employed specific search mechanisms and used additional criteria for assessing GL. Moreover, by the time we conducted this research, 49% of the GL URLs are not working anymore. Based on our findings, we discuss some challenges in using GL and potential mitigation plans. Conclusion: In this paper, we summarized the last 10 years of software engineering research that uses GL, showing that GL has been essential for bringing practical new perspectives that are scarce in traditional literature. By drawing the current landscape of use, we also raise some awareness of related challenges (and strategies to deal with them).

翻译：自软件工程师更多地使用在线通信渠道以来,软件工程(SE)研究中灰色文学(GL)最近有所增长,但对于SE研究如何利用GL.目标:这一研究旨在了解SE研究人员如何在第二期研究中使用GL。方法:我们对2011年至2018年期间在高质量软件工程会议和期刊中发表的研究成果进行了三级研究研究,然后我们运用定性和定量分析来调查446项潜在研究。结果:在446项选定研究中,126项研究引用GL,但只有95项研究用GL回答一个具体研究问题,占所有446项次级研究的近21%。有趣的是,我们发现只有少数研究采用具体的搜索机制,并使用额外的标准来评估GL。此外,在我们进行这项研究时,49%的GL URL URL 不再工作。根据我们的研究结果,我们讨论了在使用GL和潜在减缓计划方面所面临的一些挑战。结论:在这份文件中,我们总结了过去10年使用GL的软件工程研究,表明GL对于带来实际的新认识至关重要,而传统文献使用的一些挑战。