Combining noun and measure word
Stop reading that article - it is totally wrong.

The issue is that 书 and 书本 are both plural and singular at the same time. Which one it is depends solely on the context. For example, it is plural in 我常常讀書: "I read books often". In contrast, it is singular in 把書放下: "Put down the book."

You can specify plurals, however. How that actually works is that 本 is a counter for books (书). For example, 一本书 meaning "one (volume of) book". Therefore, to get plurals, you can use @windrose's example of 几本书, meaning "several (volumes of) books".

It is essentially a coincidence that the counter for books can be appended to the character for books to make 书本. Do not assume you can do this with any noun.