Ways to Specify How a Source Is "Saying"

adds concedes disagrees maintains says
agrees concludes disputes notes sees
argues condemns emphasizes observes shows
asks considers explains points out speculates
asserts contends rejects finds states
believes declares holds relates suggests
claims defends illustrates reports thinks
comments denies implies responds warns
compares derides insists reveals writes

In the context of what kind of source opinions can you use each verb?  How can your research detect those opportunities in the evidence you research?

Source: Leonard J. Rosen, Decisions: A Writer's Reference, 2nd Ed. (now out of print), N.Y.: Longman, 2002, 163-4.