This article would have been much more helpful with one exercise suggestion to work each part of the abs. Just telling me which parts to work doesn't really help when I don't know how!
i think the point of the writing was to explain what you should work out, and now that you know that there are different areas of the abs to work, you can go and search each one and find tons of exersizes for them all. one article isnt going to have all of the answers, you already looked for this one, keep searching until you find the right exersizes that fit your health level and your workout style!
I am a retired high school English teacher. I would be happy to edit Kenn's advice editorials. It's free revisions, Kenn. Punctuation is one of my English language specialities.