Lord Philip Dormer Stanhope Chesterfield, Philip Dormer Stanhope Earl of Chesterfield (1855). “The Works of Lord Chesterfield: Including His Letters to His Son, Etc : to which is Prefixed, an Original Life of the Author”, p.136
Henry David Thoreau (2017). “HENRY DAVID THOREAU – The Man, The Philosopher & The Trailblazer (Illustrated): Biographies, Memoirs, Autobiographical Books & Personal Letters (Including Walden, A Week on the Concord and Merrimack Rivers, The Maine Woods, Cape Cod, A Yankee in Canada…)”, p.1127, e-artnow