Question: When was was an English author, best known for his books about the teddy bear Winnie-the-Pooh only mystery novel published?

full_context: Document 1: A. A. Milne: Alan Alexander Milne ( ; 18 January 1882 – 31 January 1956) was an English author, best known for his books about the teddy bear Winnie-the-Pooh and for various poems. Milne was a noted writer, primarily as a playwright, before the huge success of Pooh overshadowed all his previous work. Milne served in both World Wars, joining the British Army in World War I, and was a captain of the British Home Guard in World War II.
Document 2: Alexander Lenard: Alexander Lenard (Hungarian: "Lénárd Sándor" ; Latin: "Alexander Lenardus" ; (Budapest, 9 March 1910 – Dona Emma, Brazil, 13 April 1972) was a Hungarian physician, writer, translator, painter, musician, poet and occasional language instructor. He was born in Budapest, Hungary and died in Dona Irma (Dona Emma), in the state of Santa Catarina, Brazil. He is best known as the Latin translator of A. A. Milne's "Winnie the Pooh" ("Winnie Ille Pu"). He wrote fiction and non-fiction in German, Latin, Hungarian, Italian and English.
Document 3: The Mystery of the Yellow Room: The Mystery of the Yellow Room (in French "Le mystère de la chambre jaune") is a mystery novel written by French author Gaston Leroux. One of the first locked-room mystery novels, it was first published serially in France in the periodical "L'Illustration" from September 1907 to November 1907, then in its own right in 1908.
Document 4: The Decagon House Murders: The Decagon House Murders is a 1987 Japanese mystery novel and was the debut work of author Yukito Ayatsuji. Borrowing its basic plot structure from Agatha Christie's "And Then There Were None" (Christie's book is directly referenced by some of the characters at several points), it tells the story of a group of seven university students who travel to a deserted island that was the scene of a grisly mass murder six months earlier, where events soon turn ominous. "The Decagon House Murders" belongs to the honkaku subgenre of mystery fiction.
Document 5: Winnie-the-Pooh: Winnie-the-Pooh, also called Pooh Bear, is a fictional anthropomorphic teddy bear created by English author A. A. Milne.
Document 6: The Red House Mystery: The Red House Mystery is a "locked room" whodunnit by A. A. Milne, published in 1922. It was Milne's only mystery novel.
Document 7: The Act of Roger Murgatroyd: The Act of Roger Murgatroyd: An Entertainment is a whodunit novel written by Scottish novelist Gilbert Adair first published in 2006. Set in the 1930s and written in the vein of an Agatha Christie novel, it has all the classic ingredients of a 1930s mystery and is, according to the author, "at one and the same time, a celebration, a parody and a critique not only of Agatha Christie but of the whole Golden Age of English whodunits", but also "a whodunit in its own right, so that those readers who were completely uninterested in literary games of the so-called postmodern type could nevertheless settle down comfortably with a good, gripping and intentionally old-fashioned thriller". "The Act of Roger Murgatroyd" is also a locked room mystery.
Document 8: Winnie-the-Pooh (book): Winnie-the-Pooh (1926) is the first volume of stories about Winnie-the-Pooh, by A. A. Milne. It is followed by "The House at Pooh Corner". The book focuses on the adventures of a teddy bear called Winnie-the-Pooh and his friends Piglet, a small toy pig; Eeyore, a toy donkey; Owl, a live owl; and Rabbit, a live rabbit. The characters of Kanga, a toy kangaroo, and her son Roo are introduced later in the book, in the chapter entitled "In Which Kanga and Baby Roo Come to the Forest and Piglet has a Bath". The bouncy toy-tiger character of Tigger is not introduced until the sequel, "The House at Pooh Corner".
Document 9: When We Were Very Young: When We Were Very Young is a best-selling book of poetry by A. A. Milne. It was first published in 1924, and was illustrated by E. H. Shepard. Several of the verses were set to music by Harold Fraser-Simson. The book begins with an introduction entitled "Just Before We Begin", which, in part, tells readers to imagine for themselves who the narrator is, and that it might be Christopher Robin. The 38th poem in the book, "Teddy Bear", that originally appeared in "Punch" magazine in February 1924, was the first appearance of the famous character Winnie-the-Pooh, first named "Mr. Edward Bear" by Christopher Robin Milne. In one of the illustrations of "Teddy Bear", Winnie-the-Pooh is shown wearing a shirt which was later colored red when reproduced on a recording produced by Stephen Slesinger. This has become his standard appearance in the Disney adaptations.
Document 10: In the Red (novel): In the Red is a 1989 PG Wodehouse Prize nominated black comedy-crime novel by Mark Tavener, featuring fictional BBC Reporter George Cragge and fiction Police Officer Frank Jefferson, investigating a series of murders of London bank managers, a small political party contesting a by-election, and a plan to overthrow the Director-General of the BBC.
Document 11: Christopher Robin Milne: Christopher Robin Milne (21 August 1920 – 20 April 1996) was the son of author A. A. Milne. As a child, he was the basis of the character Christopher Robin in his father's Winnie-the-Pooh stories and in two books of poems.
Document 12: Christopher Robin: Christopher Robin is a character created by A. A. Milne. He appears in Milne's popular books of poetry and Winnie-the-Pooh stories and is named after Christopher Robin Milne, the author's son. The character has subsequently appeared in Disney cartoons.
Document 13: Mystery on Fifth Avenue: "Mystery on Fifth Avenue" is the title of a "New York Times" article written by Penelope Green in June 2008 about a mystery apartment on Fifth Avenue in New York City. The apartment, a 4,200-square-foot luxury co-op formerly inhabited by Marjorie Merriweather Post and E.F. Hutton, was purchased by Wall Street mogul Steven B. Klinsky and his wife Maureen Sherry for $8.5 million. They hired architectural designer Eric Clough and his firm 212box for the renovation, during which Clough embedded an extensive mystery in the apartment in the form of riddles, ciphers, puzzles, and hidden objects, for Klinsky and Sherry's four children. It was done without his clients' knowledge, and they did not discover the mystery until several months after moving in.
Document 14: And Then There Were None: And Then There Were None is a mystery novel by English writer Agatha Christie, widely considered her masterpiece and described by her as the most difficult of her books to write. It was first published in the United Kingdom by the Collins Crime Club on 6 November 1939, as Ten Little Niggers, after the British blackface song, which serves as a major plot point. The US edition was not released until December 1939; its American reprints and adaptations were all retitled "And Then There Were None", after the last five words in the nursery rhyme "Ten Little Indians".
Document 15: The House at Pooh Corner: The House at Pooh Corner (1928) is the second volume of stories about Winnie-the-Pooh, written by A. A. Milne and illustrated by E. H. Shepard. It is notable for the introduction of the character Tigger.
ground_truth: 1922