Oliver Goldsmith, Sir James Prior (1837). “The Miscellaneous Works of Oliver Goldsmith, M.B.: Letters from a citizen of the world, to his friend in the East. A familiar introduction to the study of natural history”, p.335
Oliver Goldsmith (1856). “The Miscellaneous Works: Letters from a citizen of the world, to his friend in the East. A familiar introduction to the study of natural history”, p.116