Before revision: Copper, Silver, Gold, perhaps his most famous book Egbert B. Gebstadter is a fictional author who appears in the indexes (and sometimes in the text) of books by Douglas R. Hofstadter.
After revision: Copper, Silver, Gold, Gebstadter's first book Egbert B. Gebstadter is a fictional author who appears in the indexes (and sometimes in the text) of books by Douglas R. Hofstadter.