Citadel · Northwestern University Press
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Sherlock Holmes, Esq., and John H. Watson, M.D.: An Encyclopaedia of Their Affairs | 978-0-8101-3967-1 (0-8101-3967-7) | 2018 |
| The Sherlock Holmes Encyclopedia | 978-0-8065-0764-4 (0-8065-0764-0) | 1994 |