A strong, well-written research paper will acknowledge and consider the opposing viewpoint, and then go on to refute that position. So, for example, if you are arguing in favor of something, you want to find an article that argues against that same thing. Discuss this opposing viewpoint in your paper, and then discuss why that view point is wrong.
Pro / Con
This is NOT a library resource. This is a link to a public website. Provides the pros and cons of controversial issues. This is an Internet