No Export for You: None of the Metro 2033 Universe books are available in English, even Britannia, which was written by Rhodesian-British author, and even has an English-language comic adaptation of its prologue. Interestingly, there are several that aren't available in Russian, mostly a few written by Polish authors that were never published outside of Poland, but are still officially part of the project.
Promoted Fanboy: Everybody can potentially become one: Dmitry Glukhovsky has created the Metro 2033 Universe project, so anybody can submit their novel set in the Metro (not limited to Moscow anymore - the most popular ones not written by Dmitry himself are set in Petersburg) and if Dmitry accepts it, it is then released in Russia and becomes canon. However, due to the series' unexceptional popularity, few works become known outside Russia.
Playing Against Type: One of the reasons why Eddie Murphy chose this film was because he wanted to play serious and dramatic role in more serious action film than his previous films were.