¹ Both The Science of Deduction and The blog of Dr. John. H. Watson were created and are maintained by the BBC. Watson's blog is creative, it even has comments; but they are within the world created by Steven Moffat. That is, viewers cannot post comments. Both sites are no longer maintained by the BBC and are only available through the Wayback machine at archive.org

³ The site was maintained by The Conan Doyle Estate. At some point in 2023 the Estate probably changed hosts and web designers; therefore, the page that is found at the URL is a place holder. Links to older content are from the Wayback Machine at archive.org

⁴ The Conan Doyle Estate, at some point in 2023, redesigned its website including the URL. The domain is still commercial, but it is based in the United Kingdom. The contents and their presentation have changed significantly.

⁵ Brief definition and history of policing is now only available through the wayback machine at archive.org