John Ruskin (1800). “The Seven Lamps of Architecture: Also, Lectures on Architecture and Painting; The Study of Architecture; Sesame and Lilies; Unto this Last; The Queen of the Air; The Storm-cloud of the Nineteenth Century”
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