Arthur Conan Doyle (2007). “The New Annotated Sherlock Holmes: The Complete Short Stories: The Return of Sherlock Holmes, His Last Bow and The Case-Book of Sherlock Holmes (Non-slipcased Edition) (Vol. 2) (The Annotated Books)”, p.1430, W. W. Norton & Company
Sir Arthur Conan Doyle (2014). “Sherlock Holmes Complete Collection With illustrated Adventures of Sherlock Holmes - 4 Novels, 56 Short Stories and 120+ illustrations”, p.790, Ageless Reads
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 (2007). “The New Annotated Sherlock Holmes: The Complete Short Stories: The Adventures of Sherlock Holmes and The Memoirs of Sherlock Holmes (Non-slipcased Edition) (Vol. 1) (The Annotated Books)”, p.42, W. W. Norton & Company