I had an article published for 1st rights in a magazine. Can I use an excerpt or all of the article in my own ebook? I now own the copyright and am unsure about the rules of fair use pertaining to my own work.
It doesn't matter that it's your own work or others; if you are the copyright owner, you can re-print the entire article in your book.There is no legal obstacle to do so. If the audience of your book are different from those of the magazine, it can be convenient too.