Past Doctor Adventures
The Past Doctor Adventures (sometimes known by the abbreviation PDA or PDAs) were a series of spin-off novels based on the long running BBC science fiction television series "Doctor Who" and published under the BBC Books imprint. For most of their existence, they were published side-by-side with the "Eighth Doctor Adventures". The novels regularly featured the First through Seventh Doctors. "The Infinity Doctors" had an ambiguous place in continuity and featured an unidentified incarnation of the Doctor. The Eighth Doctor co-starred with the Fourth Doctor in one novel ("Wolfsbane") and, after the Eighth  Doctor Adventures had ceased publication, a novel ("Fear Itself") featuring the Eighth Doctor and set between two earlier Eighth Doctor Adventures ("EarthWorld" and "Vanishing Point") was published within the Past Doctor series. Publication history. Between 1991 and 1997, Virgin Publishing produced successful spin-off novels under the New Adventures and Missing Adventures ranges. However, following the "Doctor Who" television movie in 1996, the BBC did not renew Virgin Publishing's license to continue publishing "Doctor Who" material. Instead, they opted to publish their own range beginning in 1997 with "The Devil Goblins from Neptune" by Martin Day and Keith Topping . The range continued to be published through to 2005. Virgin had distinguished the New and Missing Adventures with different cover designs. BBC Books, however, did not differentiate their novels featuring the current and past Doctors in this way, although they were listed separately within the books. Fans, however, continued to distinguish the ongoing story of the Eighth Doctor from the more stand-alone adventures of past Doctors. Despite moving to the BBC, the writers (many of whom wrote for the Virgin series) have broadly attempted to maintain continuity with the New and Missing Adventures and many elements from these series  have appeared in the Past Doctor Adventures (which replaced the Missing Adventures). Indeed, one of the novels — "Millennium Shock" by Justin Richards — was a direct sequel to "System Shock", a Missing Adventure published by Virgin. Another notable release was "Scream of the Shalka", a novelisation of the webcast of the same title and the only release in the Past Doctor range that did not feature an "official" incarnation of the Doctor. "The Infinity Doctors", written by Lance Parkin, featured an unidentified Doctor. In addition to the Past Doctor Adventures and the Eighth Doctor Adventures, the BBC also published three short  story collections under the title of Short Trips, which feature all eight (at the time of publication) Doctors. These were also inherited from Virgin, a version of their Decalog short story collections, and when the BBC ceased publishing them, a licence to continue was sought by Big Finish Productions, who continued to publish their own range of Short Trips collections until 2009. The range has ceased publication. In the spring of 2005, BBC Books began publishing a series of hardcover books, the "New Series Adventures". The BBC Past Doctor paperback series continued for the remainder of 2005, but no titles  were announced after Andrew Cartmel's "Atom Bomb Blues", which was released in November 2005. In a talk in July 2006, commissioning editor Justin Richards said that BBC Books have plans for the future of the Past Doctor Adventures, but that decisions had not yet been taken. Beginning in 2012, hardback books featuring past Doctors are being published, though at a much reduced rate compared with the pre-2005 output. The books are longer, in a larger format, and written by (or in once case, adapted from earlier work by) prominent science fiction authors. As of the mid-2014, the titles published  are "Shada" by Gareth Roberts (a novelisation of the unbroadcast television story by Douglas Adams), "The Wheel of Ice" by Stephen Baxter and "Harvest of Time" by Alastair Reynolds. List of "Past Doctor Adventures". Including books featuring two of the Doctors, the numbers of books each appears in are as follows: Fourth and Seventh Doctors, 13 books each; Second and Third Doctors, 12 books each; Sixth Doctor, 11 books; Fifth Doctor, 10 books; First Doctor, 8 books; and Eighth Doctor, 2 books.