"Daniel J. Levitin Q&A: 'We've created more information in the past few years than in all of human history before us'". Interview with Lisa O'Kelly, www.theguardian.com. January 18, 2015.
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.37, e-artnow