Tony Kushner (1995). “Thinking About the Longstanding Problems of Virtue and Happiness: Essays, A Play, Two Poems and a Prayer”, p.40, Theatre Communications Group
John Muir (2015). “John Muir’s Incredible Travel Memoirs: A Thousand-Mile Walk to the Gulf, My First Summer in the Sierra, The Mountains of California, Travels in Alaska, Steep Trails… (Illustrated): Adventure Memoirs & Wilderness Studies from the Naturalist, Environmental Philosopher and Early Advocate of Preservation of Wilderness, the Author of The Yosemite and Picturesque California”, p.84, e-artnow