A lot of work is being done on what the Qur’an refers to [it is largely incomprehensible without exegesis]. Gabriel Said Reynolds has helpfully summarized some of these developments in this article. Another helpful source is this Wikipedia entry on the Syro-Aramaic Reading of the Koran. I came across another example of this dependence on the Bible today in an article about the Corpus Coranicum project:
I would love to see a version of the Qur’an in the future that fully cross-references these notional Christian sources: liturgies, Creeds and the Bible itself. That should be fascinating.