Do I need to translate Works Cited at the end?
You need to keep the reference in the original language, so that people can find it if they want to look for it. However, it's also useful for the readers to have the titles translated into English, so they can understand what they mean. Many journals specify exactly how you should cite foreign-language references this in their style guides, and many do say that you should include both translated and original titles. 

To take an extreme example, Google translates the book title


  Winning Ways for your Mathematical Plays 


into German as 


  Gewinnmöglichkeiten für Ihre mathematischen Spiele 


(which, with my limited knowledge of German, I think is a reasonably good translation). Looking these words up in the dictionary might then produce the literal translation back into English of 


  Profit Opportunities for your Math Games,


from which it would be moderately hard to identify the correct source. 

Another answer suggests (especially if it your own article you're translating) replacing foreign-language sources with equivalent English ones. I think this is intellectually dishonest, as a source that's cited in the original should also be cited in the translation. However, I don't see anything wrong with adding equivalent English sources, along with a note that they were added in translation. (There isn't any requirement that you do this, of course, but it would be of help to the reader.)