Derrick Belanger, Sir Arthur Conan Doyle (2014). “A Study in Terror: Volume 1: Sir Arthur Conan Doyle's Revolutionary Stories of Fear and the Supernatural”, p.215, Andrews UK Limited
Arthur Conan Doyle (2016). “Sherlock Holmes - The Short Stories (Book 2): The Return of Sherlock Holmes (Part 2), His Last Bow, The Case-Book of Sherlock Holmes”, p.133, BoD - Books on Demand
Arthur Conan Doyle (2014). “The Complete Sherlock Holmes (Illustrated): All 4 Novels and 56 Stories with More Than 480 Illustrations”, p.371, Top Five Books LLC