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.1443, W. W. Norton & Company
Arthur Conan Doyle (2016). “Sherlock Holmes - The Ultimate Collection: 4 Novels, 56 Short Stories & 5 Extracanonical Works”, p.345, BoD - Books on Demand
Sir Arthur Conan Doyle (2014). “Sherlock Holmes Complete Collection With illustrated Adventures of Sherlock Holmes - 4 Novels, 56 Short Stories and 120+ illustrations”, p.1483, Ageless Reads
"Ethan Hawke on ‘Regression’, ‘The Magnificent Seven’, and Playing a Space Pimp in ‘Valerian’". Interview with Sheila Roberts, collider.com. February 4, 2016.
Sir Arthur Conan Doyle (2014). “Sherlock Holmes Complete Collection With illustrated Adventures of Sherlock Holmes - 4 Novels, 56 Short Stories and 120+ illustrations”, p.1667, Ageless Reads
"The Ax Interview: Showrunners Steven Moffat And Mark Gatiss On ‘Sherlock’ And ‘Doctor Who’". Interview with Abbie Bernstein, www.assignmentx.com. November 12, 2010.
"Ethan Hawke on ‘Regression’, ‘The Magnificent Seven’, and Playing a Space Pimp in ‘Valerian’". Interview with Sheila Roberts, collider.com. February 4, 2016.