Question: What English author is known for a long series of novels that first started in 1971 and ended in 2015, where a portion of the novels focus on witches?

full_context: Document 1: Sourcery: Sourcery is the fifth "Discworld" novel by Terry Pratchett, published in 1988. On the Discworld, sourcerers – wizards who are sources of magic, and thus immensely more powerful than normal wizards – were the main cause of the great mage wars that left areas of the disc uninhabitable. As eight is a powerful magical number on Discworld, men born as the eighth son of an eighth son are commonly wizards. Since sourcerers are born the eighth son of an eighth son "of an eighth son", they are wizards squared. To prevent the creation of sourcerers, therefore, wizards are not allowed to marry or have children. The first few pages of the novel deal with a sourcerer's father who cheats death by making a prophecy that Death must honour; the alternative is to risk destroying the Discworld. The rest of the novel deals with the sourcerer's plan to have wizards rule the Discworld, and the efforts of a small group – including Rincewind the Wizard, Nijel the Destroyer and Conina the Hairdresser, daughter of Cohen the Barbarian – to thwart those plans.
Document 2: Terry Pratchett's The Colour of Magic: Terry Pratchett's The Colour of Magic is a two-part television adaptation of the bestselling novels "The Colour of Magic" and "The Light Fantastic" by Terry Pratchett. The fantasy film was produced for Sky1 by The Mob, a small British studio, starring David Jason, Sean Astin, Tim Curry and Christopher Lee as the voice of Death. Vadim Jean both adapted the screenplay from Pratchett's original novels, and served as director.
Document 3: Terry Pratchett: Sir Terence David John Pratchett, OBE (28 April 1948 – 12 March 2015), better known as Terry Pratchett, was an English author of fantasy novels, especially comical works. He is best known for his Discworld series of 41 novels. Pratchett's first novel, "The Carpet People", was published in 1971. The first Discworld novel, "The Colour of Magic", was published in 1983, after which he wrote two books a year on average. His 2011 Discworld novel "Snuff" was at the time of its release the third-fastest-selling hardback adult-readership novel since records began in the UK, selling 55,000 copies in the first three days. His final Discworld novel, "The Shepherd's Crown", was published in August 2015, five months after his death.
Document 4: The Colour of Magic: The Colour of Magic is a 1983 comic fantasy novel by Terry Pratchett, and is the first book of the "Discworld" series. The first printing of the British edition consisted of 506 copies. Pratchett has described it as "an attempt to do for the classical fantasy universe what "Blazing Saddles" did for Westerns."
Document 5: The Wee Free Men: The Wee Free Men is a 2003 comic fantasy novel by Terry Pratchett, which takes place in his Discworld setting. It is labelled a "Story of Discworld" to indicate its status as children's or young adult fiction, unlike most of the books in the "Discworld" series. A sequel, "A Hat Full of Sky", appeared in 2004 (both books were republished in a combined edition, "The Wee Free Men: The Beginning", in August 2010); a third book called "Wintersmith" appeared in 2006; and the fourth, "I Shall Wear Midnight", was released in September 2010. The final book in the series, "The Shepherd's Crown", was released in 2015.
Document 6: A Tourist Guide to Lancre: A Tourist Guide To Lancre is the third book in the "Discworld Mapp" series, and the first to be illustrated by Paul Kidby. As with the other maps, the basic design and booklet were compiled by Terry Pratchett and Stephen Briggs.
Document 7: Witches (Discworld): A major subset of the "Discworld" novels of Terry Pratchett involves the witches of Lancre. They are closely based on witches in British folklore and a slightly tongue-in-cheek reinterpretation of the Triple Goddess.
Document 8: Discworld: Discworld is a comic fantasy book series written by the English author Terry Pratchett (1948–2015), set on the fictional Discworld, a flat disc balanced on the backs of four elephants which in turn stand on the back of a giant turtle, Great A'Tuin. The books frequently parody or take inspiration from J. R. R. Tolkien, Robert E. Howard, H. P. Lovecraft, Charles Dickens, and William Shakespeare, as well as mythology, folklore and fairy tales, often using them for satirical parallels with current cultural, political, and scientific issues. The series is popular, with more than 80 million books sold in 37 languages.
Document 9: Terry Pratchett's Hogfather: Terry Pratchett's Hogfather is a two-part television film adaptation of "Hogfather" by Terry Pratchett, produced by The Mob, and first broadcast on Sky One, and in High Definition on Sky1 HD, over Christmas 2006. First aired in two 1.5-hour episodes on 17 and 18 December 2006 at 20:00 UTC, it was the first live-action film adaptation of a "Discworld" novel. In 2007, the two episodes were rerun on Christmas Eve and Christmas Day respectively on Sky One and Sky1 HD.
Document 10: Reaper Man: Reaper Man is a "Discworld" novel by Terry Pratchett. Published in 1991, it is the 11th "Discworld" novel and the second to focus on Death. The title is a reference to Alex Cox's movie "Repo Man".
Document 11: Terry Pratchett First Novel Award: The Terry Pratchett First Novel Award is a biennial award for the best unpublished science fiction novel in the Commonwealth of Nations. It is named after British author Terry Pratchett. The book is chosen by a panel of judges previously including Pratchett.
Document 12: Terry Pratchett: Sir Terence David John Pratchett, OBE (28 April 1948 – 12 March 2015), better known as Terry Pratchett, was an English author of fantasy novels, especially comical works. He is best known for his Discworld series of 41 novels. Pratchett's first novel, "The Carpet People", was published in 1971. The first Discworld novel, "The Colour of Magic", was published in 1983, after which he wrote two books a year on average. His 2011 Discworld novel "Snuff" was at the time of its release the third-fastest-selling hardback adult-readership novel since records began in the UK, selling 55,000 copies in the first three days. His final Discworld novel, "The Shepherd's Crown", was published in August 2015, five months after his death.
Document 13: Fictional universe of Harry Potter: The fictional universe of British author J. K. Rowling's "Harry Potter" series of fantasy novels comprises two distinct societies: the Wizarding World and the Muggle world. The Muggle world is the series' name for the world inhabited by the non-magical majority, with which the Wizarding World exists coextensively, albeit mostly remaining hidden from the non-magical humans. The plot of the series is set in 1990s Britain, but in a veiled and separate shadow society wherein magic is commonly used and practiced, and those who can use it live in self-enforced seclusion, hiding their abilities from the rest of the world. The term "Wizarding World" refers to the global wizard community that lives hidden in parallel with the Muggle world; the different terms refer to different communities within the same area rather than separate planets or worlds. Any new works taking place in this universe are released under the "J. K. Rowling's Wizarding World" brand.
Document 14: The Sea and Little Fishes: "The Sea and Little Fishes" is a short story by Terry Pratchett, written in 1998. It is set in his "Discworld" universe, and features Lancre witches Granny Weatherwax and Nanny Ogg. It was originally published in a sampler alongside a story called "The Wood Boy" by Raymond E. Feist, and later in a collection called "Legends".
Document 15: The Unseen University Cut Out Book: The Unseen University Cut-Out Book is a cut-out book that allows a reader to construct a replica of Unseen University from Terry Pratchett's Discworld Series. It was published on 1 October 2006, and includes a foreword by Terry Pratchett.
ground_truth: Terry Pratchett