Hey there,
Your question states: A reference book that contains articles on a wide variety of subjects, which typically focus on big-picture content, is called a(n) __________. Your correct answer would be atlas. When you look at a atlas book, or if you were to have one, you would see on how they contain things like maps, charts, and other things of that sort.
A reference book that contains articles on a wide variety of subjects, which typically focus on big-picture content, is called a(n) atlas.
Hope this helps you George.
~Jurgen