The Encyclopaedia Britannica was an Earth encyclopaedia that the Seventh Doctor kept in Smithwood Manor circa 2030. (PROSE: Warchild) The TARDIS library had at least four volumes of it by the Eighth Doctor's time. (PROSE: Seeing I)
Behind the scenes Edit
The Encyclopaedia Brittanica would later be the inspiration for a Gallifreyan encyclopaedia seen in Journey to the Centre of the TARDIS: the Encyclopedia Gallifreya, which, curiously enough, used the American spelling of "encyclopedia".