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.187, Library of America
Miyamoto Musashi, Yamamoto Tsunetomo, Inazo Nitobe (2010). “Honor: Samurai Philosophy of Life - The Essential Samurai Collection; The Book of Five Rings, Hagakure: The Way of the Samurai, Bushido: The Soul of Japan.”, p.43, Bottom of the Hill