http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
v. 1. Steffan, T. G. The making of a masterpiece.--v. 2-3. A variorum edition: Cantos I-XVII, edited by T. G. Steffan and W. W. Pratt.--v. 4. Pratt, W. W. Notes on the variorum edition.
"A survey of commentary on Don Juan": volume 4, pages 293-340.