George Bernard Shaw (2015). “The Collected Plays of George Bernard Shaw (Illustrated): Including Renowned Titles like Pygmalion, Mrs. Warren’s Profession, Candida, Arms and The Man, Man and Superman, The Inca Of Perusalem, Macbeth Skit, Caesar and Cleopatra, Androcles And The Lion”, p.2934, e-artnow
John Ruskin, Louisa Caroline Tuthill (1860). “The True and the Beautiful in Nature, Art, Morals and Religion: Selected from the Works of John Ruskin...”, p.422