First resource: One commercial/industry database (e.g. Business Insights, Gfk MRI University Reporter
Second resource: One scholarly journal article (e.g. Journal of Marketing)
Third resource: One news article from a credible source (e.g. Wall Street Journal)
Forth resource: One website (e.g. competitor website, industry trends blog, etc.)
Fifth resource: One Google Trends analysis (https://trends.google.com/trends/)