Q: Should I use only good peer-reviewed journal articles for my systematic review paper?
I want to write a systematic review paper. I have many related articles. Can I use all those articles? How many articles should I use and can it be any journal?
If you wish to write a systematic review for academic publication, you will have to primarily use peer-reviewed journal articles for your review. You will have to choose the articles based on their relevance to your review. You could choose articles based on the specific question you are addressing and also the protocol, which includes, among other things, the limits applied to your search. Generally speaking, the number of articles you can include depends on whether your journal has specified a limit to the number of references you can use.
About the kind or quality of articles to use, you can apply the same principles as above. Additionally, you can include one or two references from grey (unpublished) literature, which is often more current than published literature and likely to offer slightly different perspectives. Finally, as you are already looking at “good peer-reviewed journal articles,” I am sure you are aware of avoiding articles in predatory (bogus) journals
For more pointers on how to go about writing a sound systematic review, refer to this article: A young researcher’s guide to a systematic review