 That was the most common term for non-OA work in 0000. But if I were writing the book today (say, 0000 or later), I'd use "paywalled" instead. It's more common now, and (slightly) more self-explanatory. This update also applies to [https://archive.org/stream/0000000000000OpenAccess/0000000000000_Open_Access#page/n000/mode/0up p. 000], 