The Piano Key and Whippen | An Analysis of Their Relationships in Direct Blow Actions
Piano Technicians Guide to Field Repairs by Stephen H. Brady, RPT | Piano Technicians Guild
Piano Action Handbook - Compiled by Randy Potter | Spiral Bound Book
A Guide to Restringing - Piano Stringing Book by John W Travis
Piano Technicians Guild - Piano Technicians Journal Issues from 2006-2008 on CD