Piano Action Handbook - Compiled by Randy Potter | Spiral Bound Book
The Piano Key and Whippen | An Analysis of Their Relationships in Direct Blow Actions
Piano Technicians Guild - Vertical Regulation Curriculum, Student Workbook | A Course of Study In The Regulation of Vertical Pianos by PTG
Piano Technicians Guide to Field Repairs by Stephen H. Brady, RPT | Piano Technicians Guild
Piano Technicians Guild - Grand Regulation Curriculum, Student Workbook | A Course of Study In The Regulation of Grand Pianos by PTG