Batman: The Dark Knight Returns is 1986 comic story about Batman coming out of retirement as a superhero. Superman is featured heavily in books three and four.
Batman: The Dark Knight was originally released as a four issue limited series in 1986. It has since been published in collected editions as Batman: The Dark Knight Returns, the title of the first issue. The story now is very often referred to in the media as just The Dark Knight Returns or by its creators, simply Dark Knight.