Martin Heidegger, Simone de Beauvoir, Jean-Paul Sartre (2016). “The Philosophical Library Existentialism Collection: Essays in Metaphysics, The Ethics of Ambiguity, and The Philosophy of Existentialism”, p.99, Open Road Media
Henry David Thoreau (2017). “Journeys, Adventures & Life in Harmony with Nature – 6 Book Collection (Illustrated): Including Walden, A Week on the Concord and Merrimack Rivers, The Maine Woods, Cape Cod, A Yankee in Canada & Canoeing in the Wilderness - North American Highlands Series”, p.199, e-artnow