Look for missing pieces of information in the sources you have. Is there information you need that you haven't found? Or that isn't available?

Do you have:

Background sources?

These offer evidence for general statements and context for other sources.

Current sources?

What counts as current will depend on your topic, but your sources should be up-to-date.

Academic and fact-based sources?

These establish credibility for your argument.

Statistical Sources?

These provide detail and data to strengthen your argument.