[Child of the 7th Age]

Regarding the inclusion of Ruth Noel's book. My guess is that they felt compelled to list something dealing explicitly with languages. The problem is that the best language resources are now websites on the computer rather than printed sources. There really hasn't been anything recent in a one-volume format that gives you an overview of how Tolkien handled languages (or for that matter even Sindarin and Quenyan by themselves). (There's the very old Allan book and the more recent book on Sindarin, which a lot of people don't like because of the liberties taken by David Salo in the movies.)

There may be several reasons for this dearth of titles. There is less of a market for this type of resource so, without the promise of large profits, publishers haven't put out much. Secondly, there is the problem that a fairly small group has been given exclusive access to Tolkien's language manuscripts. Gradually, those things have been coming out in Vinyar Tengwar but I haven't heard of anyone working on an overall synthesis or general appraisal. Noel's book is the only one I can think of as old and flawed as it is....unless someone knows of something else.