Question: Who wrote the novel that was the basis for the movie that Morfydd Clark played Frederica Vernon in?

Context articles: Glenn Clark
The Call Up (film)
Allan Clark
Interlude in Prague
Morfydd Clark
Milton Clark
Love &amp; Friendship
Bobby Clark (footballer)
Dwight Clark
Dad Clark

Glenn Clark (born December 1, 1969 in Pickering, Ontario) is the head coach of the New England Black Wolves and the former head coach of the Toronto Rock of the National Lacrosse League.
 He was also a former NLL player.
 Clark played in the NLL from 1998-2006 for both the Rock and the Philadelphia Wings.
 With the Rock, Clark won five NLL Championships.
 He also appeared in three National Lacrosse League All-Star Games, two with the Rock, and one with the Wings.
 In 2003, Clark played for Team Canada as they won the World Indoor Lacrosse Championships.
 In 2011, he became goaltending coach for Team Canada.
The Call Up is a 2016 British science fiction thriller film written and directed by Charles Barker.
 It stars Max Deacon, Morfydd Clark, Ali Cook, Parker Sawyers, Tom Benedict Knight, Boris Ler, Douggie McMeekin, and Adriana Randall as top-ranked gamers who are invited to beta test a new first-person shooter virtual reality game.
 When they discover the equipment includes lethal feedback, they must win the game to survive.
 The film premiered at the Brussels International Fantastic Film Festival and was released in the UK on 20 May 2016.
Allan Vincent Clark (born June 8, 1957 in Grand Rapids, Minnesota) is a former American football running back in the National Football League who played for the New England Patriots, the Green Bay Packers, and the Buffalo Bills.
 Clark played collegiate ball for Northern Arizona University before being drafted by the New England Patriots in the 10th round of the 1979 NFL Draft.
 Clark played professionally for 3 seasons and retired in 1982.
Interlude in Prague is a 2017 film about Wolfgang Amadeus Mozart starring Aneurin Barnard, James Purefoy, Samantha Barks, Morfydd Clark, Adrian Edmondson and Anna Rust.
 It was directed by John Stephenson, written by Brian Ashby, and screenplay by Brian Ashby, Helen Clare Cromarty, and John Stephenson.
Morfydd Clark is a Welsh actress.
 She trained at The Drama Centre, London, leaving in her final term to play the title role in Saunders Lewis' play "Blodeuwedd" with Theatr Genedlaethol Cymru.
 She has appeared in "Violence and Son" at the Royal Court, as Juliet in "Romeo and Juliet" at the Crucible Theatre, Sheffield, and in "Les Liaisons Dangereuses" at the Donmar Warehouse.
 She played Frederica Vernon in Whit Stillman's film "Love & Friendship".
Milton Clark (born 27 June 1922) is a former Australian rules footballer who played with Essendon and North Melbourne in the Victorian Football League (VFL).
 He was on Essendon's list from 1939, but his football career was restricted due to his service in the armed forces during World War II.
 Clark played in Essendon's reserves premiership in 1941 and played three senior games for the Bombers in 1945.
 He transferred to North Melbourne for the 1946 where he played tow further VFL matches.
 Clark later played for several season with Essendon RSL after leaving the VFL.
 He worked as a fibrous plasterer until retiring in 1982.
Love & Friendship is a 2016 period comedy film written and directed by Whit Stillman.
 Based on Jane Austen's epistolary novel "Lady Susan", written ca. 1794, the film stars Kate Beckinsale, Chloë Sevigny, Xavier Samuel, and Stephen Fry.
 The film follows recently widowed Lady Susan in her intrepid and calculating exploits to secure suitably wealthy husbands for her daughter and herself.
 Although adapted from "Lady Susan", the film was produced under the borrowed title of Austen's juvenile story "Love and Freindship" ["sic"] .
Robert Brown Clark (born 26 September 1945 in Glasgow) is a Scottish football player and coach.
 Clark, who played as a goalkeeper, spent most of his playing career with Aberdeen.
 He also played for Queen's Park, Washington Whips, San Antonio Thunder and Clyde.
 Clark played 17 times for Scotland and represented the Scottish League.
 He later became a coach, mainly working in New Zealand and the United States.
Dwight Edward Clark (born January 8, 1957) is a former American football wide receiver and executive.
 He played for the San Francisco 49ers of the National Football League (NFL) from 1979 to 1987.
 With the 49ers, Clark played on two Super Bowl championship teams.
 He caught the winning touchdown pass thrown by quarterback Joe Montana in the NFC Championship Game in January 1982 against the Dallas Cowboys.
 The play, immortalized as "The Catch," propelled the 49ers to their first Super Bowl championship.
 Clark played college football at Clemson University before being drafted by the 49ers in the 10th round of the 1979 NFL Draft.
 He served as the general manager of the 49ers in 1998 and in the same capacity with the Cleveland Browns from 1998 to 2002.
Alfred Robert "Dad" Clark (July 16, 1873 – July 26, 1956) was a professional baseball player.
 Clark played part of one season in Major League Baseball for the Chicago Orphans in 1902.
 He played in 12 games, collecting 8 hits in 43 at-bats, totaling a .186 batting average.
 Along with his nickname Dad, Clark also was known as "Fred", a shortened version of Alfred.