The piano Hammer: A detailed investigation into an important facet of piano manufacturing (Das Musikinstrument : Technical book series ; v. 34): Pfeiffer, Walter: 9783920112619: Amazon.com: Books
Pianos Inside Out: A Comprehensive Guide to Piano Tuning, Repairing, and Rebuilding: Mario Igrec, Richard Lehnert: 9780982756300: Amazon.com: Books