Can I reference or mention Doctor Who and Star Wars in my books? I have read many books that do, but I didn't know if they had to get permission for that.
Yes, you can use the titles of other works, but you may have to include a works cited list in your end matter, depending on how the name is used and how often. However, if you just have a character saying "I'd just been to see the new Star Wars movie, so I didn't think anything of the alien crossing the street," you really don't have to do anything else but to treat the title appropriately. The other thing is, adding popular titles will date your book, and doing so is generally discouraged.
