http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
"Preface" by Austin Clarkson (p. i-iii) and "On performing Battle Piece" by David Tudor (p. iv-vi) dated 1995.
"Critical notes" by Austin Clarkson, pages 59-67.