Mechanical Advantage Series by John Middendorf
Climbing Tools and Techniques—1908 to 1939-Aid Climbing Mastery (Europe, PartB 1st draft)
Great series on climbing history by John Middendorf — Alpine Savvy
Climbing Tools and Techniques—1908 to 1939 (Europe, PartA) Myths and Legends
The Different Types of [Rock] Climbing
INDEX to Mechanical Advantage series - by John Middendorf
Climbing Tools and Techniques—1908 to 1939-Aid Climbing Mastery (Europe, PartB 1st draft)
Climbing Tools and Techniques—1908 to 1939 (Europe, PartA) Myths and Legends
Climbing Tools and Techniques—1908 to 1939-Aid Climbing Mastery (Europe, PartB 1st draft)
Climbing Tools and Techniques—1908 to 1939 (Europe, PartA) Myths and Legends