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 Both sites are no longer maintained by the BBC and are only available through the Wayback machine at archive.org

² h2g2,cofounded by Douglas Adams, stands for The Hitchhiker's Guide to the Galaxy - an unconventional guide to Life, The Universe and Everything. This site - the Earth Edition of the Guide - is an encyclopedic project contributed to by people from all over the world. h2g2.com was launched in April 1999, and the BBC took over the running of the site in February 2001 as part of a drive to develop new and innovative online services (The h2g2 Tour accessed October 28, 2010). Links updated June 2024

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 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 his presentation have changed significantly.

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