Thank God we have a professional author around to guide us. What Sheldon wrote makes more sense than anything else I read about [[List of...]].
Uncle Ed
I've been wanting to avoid wading into this discussion, but the term "Americans" does have a double meaning, and its usage as a reference solely to U.S. citizens rankles with some people from Canada, Mexico and other parts of North and South America who also consider themselves "American" as well. The term is commonly used in reference U.S. citizens, and it doesn't particularly offend me personally, but I know people who object to it.
Using "Americans" in reference to U.S. citizens is a bit like using "Indians" in reference to Native Americans or "cripples" in reference to the physically disabled. I know there are people who find it silly and irritating that they should be asked to use more "politically correct" language, but whenever possible I think it's best to be sensitive about these things. I don't see a downside to saying "United States citizens." It's precise, unambiguous and offends no one. That would be my preferred usage.