Dear Mr. Brown: You might add to your Sordello bibliography my book,
Browning and Italy by Jacob Korg,Ohio University Press, Athens,
Ohio,1983.It has no references to Pound, but there are
about 20 pages on Sordello.
        Sordello is also discussed in my article, "The Music of Lost
Dynasties: Browning, Pound and History, ELH, Vol 39 No. 3. September,
1972, 420-440.