Hi There! I am currently writing a book to about exercise! I want to sell it commercially, so before I go and try to get it published, I wanted to know a few things. I wanted to include a study I found that shows which exercise workouts are better than others, but I do not know if I would have to pay them royalties even if I do cite my source. Without getting too specific, it is a study from a college that was conducted by one of the professors. Also, I wanted to talk about in my book how Michael Phelps eats 12,000 calories a day and show what he eats for breakfast. It is in his biography "Beneath The Surface." Can I do this without violating copyright if I cite the source, or is it a violation no matter what? I have tried looking up to see information on copyright and royalties, but I want to make sure I am not getting anything wrong. I know that with songs, for example, writers cannot cite more than a lyric or two and publishers will stay far away from you if you try even doing so. Is trying to cite a scientific study the same thing? What about citing information from another book? Sorry, if this is obvious information to everyone here, but I want to make sure I get this right. Thanks!