Cover Art for Ebooks - Is it acceptable to use images labeled by google as "for reuse with modifications"

I want to put photos of 3 celebrity sportsmen on the cover of an eBook that I intend to self-publish on amazon and other stores, and I wonder if images that are returned by Google image search with license (under 'search tools') labelled as "for reuse" or "for reuse with modification" are fair game? Can I just use them and be free of any obligations?