How to Cite: Paraphrasing
What would you do if say person A has paraphrased person B's work and you want to directly quote what person A has written?
Answer
You should always try to find the primary source however, if you read an article which refers to a different article, only cite the article you have read.
See page 13 of the Cite It Right guide, section 2.2.9 for more information.