Anthony, Michael. “SPCO Delves into Mysteries of Universe; Beethoven Paired Nicely with Ives’ ‘Unanswered Question’: Metro Edition.” Star Tribune, February 8, 2004.
Clements, Andrew. “Review: Ives’s Masterpiece Makes Rare Appearance: Classical: Pierre-Laurent Aimard: Aldeburgh Festival 5/5.” The Guardian, June 16, 2004, 26.