You must include attribution to the image creator under each image that you use in Book Creator...even those found in the Public Domain. There are some simple ways to do this. Check out the options below.
GO BEYOND GOOGLE!
Try Sweet Search for better research results.
Use the Middle Search Plus database and the online World Book and Britannica encyclopedias found on the library website Research Tab to find even more great info.
Image by macrovector on Freepik