Working from a bibliography in another aper is not plagiarism.  It's actually a pretty good research technique.  As you read those papers, check *their* bibliographies, too, and 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.  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.