Richard Salter Storrs (1875). “Conditions of Success in Preaching Without Notes: Three Lectures Delivered Before the Students of the Union Theological Seminary, New York, Januray 13, 20, 27: 1875; with an Appendix”, p.114
John Hughlings Jackson (1931). “Selected Writings of John Hughlings Jackson: Evaluation and dissolution of the nervous system. Speech. Various papers, addresses and lectures”