2. Literature review

Once you've found the right keywords & some main papers, try to find reviews.

• Literature reviews qualitatively review all the papers on a topic.
• Meta-analyses try to collect effects from multiple papers on the topic to give a quantitative answer.
• Textbooks are used to present the field the way experts want a beginner to learn about it.

It can be helpful to type a keyword with the words "review" or "meta-analysis" in Google Scholar.