Before deciding what resources to incorporate into your literature review, you must evaluate them to ensure the information they contain is authoritative, reliable and relevant.
Researchers should remain objective about their work. In deciding what information to include in the literature review, you should ...
keep an open mind
represent both sides of a contentious idea
consider work that runs counter to your own research hypothesis
Look critically at each article, book, or other form of information. For each item that you might include in your review, ask:
Some other questions to consider
Now, step back and ask yourself, is this appropriate for your purpose?