George Orwell, Peter Hobley Davison (2001). “Orwell and politics: Animal farm in the context of essays, reviews and letters selected from the complete works of George Orwell”, Penguin Modern Classics
George Orwell, Peter Hobley Davison (2001). “Orwell and politics: Animal farm in the context of essays, reviews and letters selected from the complete works of George Orwell”, Penguin Modern Classics
George Orwell (2001). “The Complete Novels of George Orwell: Animal Farm, Burmese Days, A Clergyman's Daughter, Coming Up for Air, Keep the Aspidistra Flying, Nineteen Eighty-Four”, p.21, Penguin UK