Develop a plan before you go looking. It is useful to have more than one idea. Just any article or web site won't do. It must be substantive and present information respected in your professional context. You will probably want to find your article in a publication which is specialized to your field or problem situation.
Length can be a good indication of substance.
Read it carefully, underlining, annotating, mapping its content. Your task at this stage is to understand it and interpret its relevance thoroughly. I want you to hand in the article and your planning materials to me. You know you will need to do more than just indicate its content briefly. You will want to remind your readers of the situation this article relates to.