Question: Who was the author of the book, on which Channel 4's 1982 film, for which Howard Blake wrote the soundtrack. is based ? 

full_context: Document 1: Blair Packham: Blair Packham is a veteran Canadian singer/songwriter. He was lead vocalist/guitarist for The Jitters in the 1980s and has released material as a solo singer/songwriter since 2000. He has also written music and lyrics for numerous films and television programs, including TSN’s "NHL Tonight!," Global Television’s "The Jane Show," as well as animated shows like "Beyblade," "Rescue Heroes," "Trucktown," "Spliced!," and "The Adventures of Chuck and Friends". Blair is a co-host (with Bob Reid) for Newstalk 1010's "In the Studio". With Ron Sexsmith, he co-produced an Andy Kim Christmas track, as well as albums for U.K. singer/songwriter Max Croft, R&B/soul singer Stacey Kaniuk, hardcore band Youth Youth Youth and many others. As a volunteer, Blair served as co-Vice-President of the Songwriters Association of Canada from 2000 to 2007. He is one of the organizers, along with Rik Emmett, of the annual SongStudio, an intensive, week-long songwriting workshop in Toronto, Ontario. In addition to being a lifelong SOCAN member, Blair is also a member of the Canadian Music Creators Coalition.
Document 2: James Blake (musician): James Blake Litherland (born 26 September 1988), known as James Blake, is an English singer, songwriter, musician and record producer from London. He first received recognition in 2010 for a trio of dubstep-influenced EPs, and the following year his self-titled debut album was released in the United Kingdom to critical praise. His second studio album "Overgrown" was released in 2013 and was awarded the Mercury Prize. He released his third studio album "The Colour in Anything" in 2016. Blake has also released remix work under the alias Harmonimix.
Document 3: Father Christmas (comics): Father Christmas is a British children's picture book written and drawn by Raymond Briggs and published by Hamish Hamilton in 1973. Briggs won the annual Kate Greenaway Medal from the Library Association, recognising the year's best children's book illustration by a British subject. For the 50th anniversary of the Medal (1955–2005), a panel named it one of the top ten winning works, which composed the ballot for a public election of the nation's favourite.
Document 4: Ug (book): Ug is a children's book by Raymond Briggs. In 2001 it won the Nestlé Smarties Book Prize Silver Award.
Document 5: John Williams: John Towner Williams (born February 8, 1932) is an American composer, conductor, and pianist. With a career spanning over six decades, he has composed some of the most popular and recognizable film scores in cinematic history, including "Jaws", the "Star Wars" series, "Close Encounters of the Third Kind", "Superman", "E.T. the Extra-Terrestrial", the "Indiana Jones" series, the first two "Home Alone" films, the first two "Jurassic Park" films, "Schindler's List", and the first three "Harry Potter" films. Williams has been associated with director Steven Spielberg since 1974, composing music for all but three of his feature films. Other notable works by Williams include theme music for the Olympic Games, "NBC Sunday Night Football", "The Mission" theme used by NBC News, the television series "Lost in Space" and "Land of the Giants", and the incidental music for the first season of "Gilligan's Island". Williams has also composed numerous classical concertos and other works for orchestral ensembles and solo instruments. From 1980 to 1993, he served as the Boston Pops' principal conductor, and is now the orchestra's laureate conductor.
Document 6: The Snowman (fairy tale): "The Snowman" is a literary fairy tale by Hans Christian Andersen about a snowman who falls in love with a stove. It was published by C.A. Reitzel in Copenhagen as "Sneemanden" on 2 March 1861. Andersen biographer Jackie Wullschlager describes the tale as a lyrical and poignant complement to Andersen's "The Fir-Tree" of December 1844.
Document 7: The Snowman: The Snowman is a children's picture book without words by English author Raymond Briggs, first published in 1978 by Hamish Hamilton in the United Kingdom, and published by Random House in the United States in November of the same year. In the UK, it was the runner up for the Kate Greenaway Medal from the Library Association, recognising the year's best children's book illustration by a British writer.
Document 8: Father Christmas (1991 film): Father Christmas is a 1991 animated short based on two books written by Raymond Briggs: "Father Christmas" and "Father Christmas Goes on Holiday", published in 1973 and 1975 respectively. It was first aired in Britain in 1991 on Channel 4, nine years after "The Snowman", another animated Briggs adaptation produced for the same channel. This movie was dedicated to the late actor John McGuire. The film was first released on DVD in 2000, bundled with "The Snowman". It was later released separately.
Document 9: Walking in the Air: "Walking in the Air" is a song written by Howard Blake for the 1982 animated film of Raymond Briggs' 1978 children's book "The Snowman". The song forms the centrepiece of "The Snowman", which has become a seasonal favorite on British and Finnish television. The story relates the fleeting adventures of a young boy and a snowman who has come to life. In the second part of the story, the boy and the snowman fly to the North Pole. "Walking in the Air" is the theme for the journey. They attend a party of snowmen, at which the boy seems to be the only human until they meet Father Christmas with his reindeer, and the boy is given a scarf with a snowman pattern. In the film, the song was performed by St Paul's Cathedral choirboy Peter Auty, and reissued in 1985 (on Stiff Records) and 1987.
Document 10: Benjamin Britten: Edward Benjamin Britten, Baron Britten {'1': ", '2': ", '3': ", '4': "} (22 November 1913 – 4 December 1976) was an English composer, conductor and pianist. He was a central figure of 20th-century British classical music, with a range of works including opera, other vocal music, orchestral and chamber pieces. His best-known works include the opera "Peter Grimes" (1945), the "War Requiem" (1962) and the orchestral showpiece "The Young Person's Guide to the Orchestra" (1945).
Document 11: Howard Blake: Howard Blake OBE (born 28 October 1938) is an English composer, conductor, and pianist whose career has spanned more than 50 years and produced more than 650 works. Blake's most successful work is his soundtrack for Channel 4’s 1982 film "The Snowman" including the song "Walking in the Air". He is increasingly recognised for his classical works including concertos, oratorios, ballets, operas and many instrumental pieces.
Document 12: The Man (comics): The Man is a graphic novella for children, written and illustrated by Raymond Briggs and published by Julia MacRae Books in 1992. It tells the humorous story of a boy, John, who is visited by the titular Man, a minuscule human (homunculus) who arrives in the boy's bedroom unclothed and hungry. After getting over his initial shock, the boy starts to take care of him. The story follows their relationship over the next few days between John and 'Man', with the Man showing himself to be demanding, bossy and messy, but nevertheless a bond forms between the pair. Their time together involves many funny and peculiar moments, such as an odd obsession with Frank Cooper's Oxford marmalade, using socks for jumpers, and a near-death collision with a marmalade jar.
Document 13: Raymond Briggs: Raymond Redvers Briggs, CBE (born 18 January 1934) is an English illustrator, cartoonist, graphic novelist and author who has achieved critical and popular success among adults and children. He is best known in Britain for his story "The Snowman", a book without words whose cartoon adaptation is televised and whose musical adaptation is staged every Christmas.
Document 14: The Year Without a Santa Claus: The Year Without a Santa Claus is a 1974 Christmas stop motion animated television special produced by Rankin/Bass Productions. The story is based on Phyllis McGinley's 1956 book of the same name, illustrated by Kurt Werth. It was originally broadcast on December 10, 1974 on ABC.
Document 15: Blake Torney: Blake Torney is an American producer, director, actor and entertainer. His prestigious career includes theatre, film, television, and nightclubs. Blake has worked with film directors Alfred Hitchcock, Franco Zeffirelli, Hal Ashby, John Frankenheimer, Barry Levinson and Paul Verhoven. His dancing and singing skills have enlivened audiences and given him the opportunity to work with Tom Jones, Janis Joplin, Michael Jackson, and Sammy Davis Jr. among others. Blake is a 4th generation San Franciscan. Born in Northern California with his twin brother Kirkham Wright. Along with his older brother, musician Ned Torney, Blake has performed and recorded some of his, and Kirk's, original music. He's also an accomplished guitarist who sings and plays music with his son Orion FreedomSong and Django Gurley, performing at festivals and other venues. Since 1974, Blake has directed and performed children's educational projects with Bethany Argisle's "Moment Museum".
ground_truth: Raymond Briggs,