Walter Bagehot (1873). “Physics and Politics: Or, Thoughts on the Application of the Principles of "natural Selection" and "inheritance" to Political Society”, p.43
Charlotte Bronte, Emily Bronte, Anne Bronte (2009). “The Bronte Sisters: Three Novels: Jane Eyre; Wuthering Heights; and Agnes Grey (Penguin Classics Deluxe Edition)”, p.311, Penguin