Joseph Butler, Stephen L. Darwall (1983). “Five Sermons, Preached at the Rolls Chapel and A Dissertation Upon the Nature of Virtue”, p.47, Hackett Publishing
Walter Savage Landor (1876). “Miscellaneous poems: Collection of 1846. Last fruit off an old tree. Dry sticks. Additional poems. Criticisms: Idyls of Theocritus. Poems of Catullus. Francesco Petrarca”, p.222