Working from a bibliography in another paper is not plagiarism.  It's actually a pretty good research technique.  As you read those papers, check *their* bibliographies, too, and so on.  Pretty soon you will have pretty thorough coverage.

Do note that you cannot just plop those 50-60 or so references into your own bibliography but do nothing else, nor paraphrase what someone else has said about them, but without reading them.  That's called reference padding and is academic misconduct.  You have to actually *read* the papers.  When you do that, you may find that some of them don't fit your needs as well as you may have at first thought.