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.62, Open Road Media
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.61, Open Road Media