I have had a hard back version of The Everlasting Circle since 1974...my first wife bought it for me as a birthday present.
By contrast I bought a paperback version of The Idiom of the People in a Cape Cod bookshop about 10 years ago.
As Nick correctly said......They are useful as a reference, and you can access all the raw data you need on The Full English web site.

I would add that in The Everlasting Circle is the only reference to the Version of "Bonny" collected from James G. Bounds where he sung - "John Brown's War" in the chorus instead of the more normal - "Jean Francois". This is the ONLY version of this collected by Gardiner.

Tim Radford