Sir Arthur Conan Doyle (2014). “Sherlock Holmes Complete Collection With illustrated Adventures of Sherlock Holmes - 4 Novels, 56 Short Stories and 120+ illustrations”, p.865, Ageless Reads
Arthur Conan Doyle (2016). “Sherlock Holmes - The Novels: A Study in Scarlet, The Sign of the Four, The Hound of the Baskervilles, The Valley of Fear”, p.30, BoD - Books on Demand