Andrew Dickson White (2012). “A History of the Warfare of Science with Theology in Christendom: From Creation to the Victory of Scientific and Literary Methods”, p.40, Transaction Publishers
"Principles of political economy considered with a view to their practical application". Book by Thomas Robert Malthus, Book II, Chapter I, "On the Progress of Wealth", Section I, p. 309, 1836.
Society for Psychical Research (Great Britain), Society for Psychical Research (London, England), Henry Sidgwick, Balfour Stewart, Arthur James Balfour Balfour (Earl of) (1912). “Presidential Addresses to the Society for Psychical Research, 1882-1911”