Argument
Authors: Are their credentials similar or different?
Occasion: are the sources similar in occasion and relevancy?
Topic: Are they discussing the same topic?
Purpose: Is the purpose the same or different? Is one more effective than others?
Argument and conclusions: What is the argument? Are the conclusions the same, different, or close?
Examples: What types of examples did they use?
Solutions: what are they? Are they the same or different?