Work used in books, articles or other (print) media or mainstream news sites etc.

Some of my images have been used in (printed) books, articles or online (news) media, sometimes because there are not too many images of the subject around, but often also just due to the fact that my images are available under a CC0 "Public Domain" license. As such, I don't often get messages concerning the usage, but every now and then I stumble on an image being used somewhere...