A secondary source article will give you clues about the primary source that is based on. Look for these pieces of information:
1. Journal Title – not always given
2. Keywords – what the article is about
3. Author - usually the researcher quoted in the article.
4. Publication Date – sometimes given, sometimes based on the date of the magazine or newspaper.
5. Affiliation - almost always given. This refers to the university or hospital where the researcher works.