John Muir (1997). “Nature Writings: The Story of My Boyhood and Youth, My First Summer in the Sierra, the Mountains of California, Stickeen, Selected Essays”, p.721, Library of America
Ed Viesturs, David Roberts (2011). “The Will to Climb: Obsession and Commitment and the Quest to Climb Annapurna--the World's Deadliest Peak”, p.87, Crown