Ralph Waldo Emerson, Robert Ernest Spiller, Alfred Riggs Ferguson, Joseph Slater, Jean Ferguson Carr (1971). “The Collected Works of Ralph Waldo Emerson”, p.315, Harvard University Press
Louisa May Alcott (2015). “Civil War Memoirs of Louisa May Alcott (Unabridged): Including Letters, Hospital Sketches & Biography of the Author – Autobiographical account of the author from the time she worked as a volunteer nurse for the Union Army during the American Civil War”, p.187, e-artnow