Every once and a while I would come upon a word in the book that was highlighted or underlined. I realize this is a tiny nitpick, but it is "once in a while" n

Every once and a while I would come upon a word in the book that was highlighted or underlined. I realize this is a tiny nitpick, but it is "once in a while" not "once and a while"; the latter isn't even grammatical. The article is otherwise very good.