Note: Some sources may discuss only part of your thesis. This is normal. When analyzing a potential source, ask yourself, "How could I use this in my paper?" or "Is there anything in this source that is compelling, surprising, overwhelmingly strong, or unusual related to my topic?"
Look in the "literature review" section of a supporting article you have already found. Most academic journal articles include a literature review section, which may or may not be labeled. In this section, the authors summarize all of the recently published literature/research on the topic. Often you can find a counterargument listed there.
Add one of the following keywords to your search: concerns, costs, negative effects, criticisms, etc.