Michael Benjamin Berger, Henry David Thoreau (2000). “Thoreau's Late Career and The Dispersion of Seeds: The Saunterer's Synoptic Vision”, p.83, Camden House
Henry David Thoreau (2014). “Citizen Thoreau: Walden, Civil Disobedience, Life Without Principle, Slavery in Massachusetts, A Plea for Captain John Brown”, p.132, Graphic Arts Books