Sometimes they print what's there and send it along with their article. Any editor is happy to see images with text. You have to evaluate them together. Library Research Culleton, Lindstrom, and Hogan stress that the Internet should not be an author's only source of information. However, knowing how to restrict your search on the Internet is essential.
Historical information is still better researched at libraries.
Lindstrom echoes those comments on the importance of library research. She draws an analogy to the difference between television news and the print media. I tend to look for book information first. It's like watching the evening news or reading the evening newspaper. Hogan notes that a science author can establish credibility by reading the original scientific reports.