Do Science fiction writers have to make bibliographies?

I know that when writing a good science fiction novel, people have to do a lot of research in order to make some of the technology and events that they describe more realistic. A lot of people don't just have this knowledge sitting around in their heads, so they have to do outside research. Do they have to do "Works Cited" or anything in order to give credit to the research they used, even though their novels are fiction?