The Magical Worlds of Harry Potter: A Treasury of Myths, Legends, and Fascinating Facts is a guide to the fictional "Harry Potter" universe, written by David Colbert.
 It explores the references to history, legends, and literature in J.K. Rowling's "Harry Potter" novels.
 Colbert conceived the idea for "The Magical Worlds of Harry Potter" while quizzing his nephew and nieces about the mythological references in the novels.
 He later wrote the book while teaching a seminar on self-publishing to graduate students at the University of North Carolina.
 The book was published in March 2001, without approval from Rowling, and has since received positive reviews from critics.
 An updated version of "The Magical Worlds of Harry Potter" was published in 2004 by Berkley Books.
Warner Bros.
 Entertainment, Inc. and J. K. Rowling v. RDR Books, 575 F.Supp.2d 513 (SDNY 2008) is a copyright lawsuit brought on 31 October 2007 by the media company Warner Bros. and "Harry Potter" author J. K. Rowling against RDR Books, an independent publishing company based in Muskegon, Michigan.
 Lawyers for Rowling and Time Warner argued that RDR's attempt to publish for profit a print facsimile of "The Harry Potter Lexicon", a free online guide to the "Harry Potter" fictional universe, constituted an infringement of their copyright and was not protected by the affirmative defense of fair use.
 The trial was held from 14–17 April 2008 in the United States District Court for the Southern District of New York.
 In September 2008, the court ruled in Rowling's favor, and publication of the book was blocked.
 In 2009, RDR Books released an edited volume, eliminating the problematic long quotes found to be infringing.
Harry Potter and the Deathly Hallows is the seventh and final novel of the "Harry Potter" series, written by British author J. K. Rowling.
 The book was released on 21 July 2007, ten years after publication of "Harry Potter and the Philosopher's Stone" (1997), by Bloomsbury Publishing in the United Kingdom, in the United States by Scholastic, and in Canada by Raincoast Books, ending the series that began in 1997 with the publication of "Harry Potter and the Philosopher's Stone".
 The novel chronicles the events directly following "Harry Potter and the Half-Blood Prince" (2005), and the final confrontation between the wizards Harry Potter and Lord Voldemort, as well as revealing the previously concealed back story of several main characters.
 The title of the book refers to three mythical objects featured in the story, collectively known as the "Deathly Hallows"—an unbeatable wand, a stone to bring the dead to life, and a cloak of invisibility.
The immense popularity and wide recognition of J. K. Rowling's Harry Potter fantasy series has led to its being extensively parodied, in works spanning nearly every medium.
 The franchise holds the record for the most fan fiction parodies, at over 900.000 Some self-described parodies have been targeted by Rowling and her publishers as plagiarism, while others have sold hundreds of thousands of copies without any threat of legal sanction.
 Misinterpretations of "Harry Potter" parodies have sparked at least two urban legends.
 Many "Harry Potter" parodies are self-published; others are put out as part of major comic productions, such as "Mad", "The Simpsons", "South Park", "Saturday Night Live" and "Robot Chicken", all of which have parodied "Harry Potter" several times.
 Rowling has also been parodied (and parodied herself) in a number of instances.
Joanne Rowling, {'1': ", '2': ", '3': ", '4': "} ( ; born 31 July 1965), who writes under the pen names J. K. Rowling and Robert Galbraith, is a British novelist and screenwriter who wrote the "Harry Potter" fantasy series.
 The books have won multiple awards, and sold more than 400 million copies.
 They have become the best-selling book series in history and been the basis for a series of films, over which Rowling had overall approval on the scripts and was a producer on the final films in the series.
Harry Potter is a British-American film series based on the "Harry Potter" novels by author J. K. Rowling.
 The series is distributed by Warner Bros. and consists of eight fantasy films, beginning with "Harry Potter and the Philosopher's Stone" (2001) and culminating with "Harry Potter and the Deathly Hallows – Part 2" (2011).
 A spin-off prequel series will consist of five films, starting with "Fantastic Beasts and Where to Find Them" (2016).
 The "Fantastic Beasts" films mark the beginning of a shared media franchise known as J. K. Rowling's Wizarding World.
Fantastic Beasts and Where to Find Them is a 2001 book written by British author J. K. Rowling (under the pen name of the fictitious author Newt Scamander) about the magical creatures in the "Harry Potter" universe.
 The original version purports to be Harry Potter's copy of the textbook of the same name mentioned in "Harry Potter and the Philosopher's Stone" (or "Harry Potter and the Sorcerer's Stone" in the US), the first novel of the "Harry Potter" series.
 It includes several notes inside it supposedly handwritten by Harry, Ron Weasley, and Hermione Granger, detailing their own experiences with some of the beasts described, and including in-jokes relating to the original series.
Mary Catherine Gordon (born December 8, 1949) is an American writer and the McIntosh Professor of English at Barnard College.
 She is best known for her novels, memoirs and literary criticism.
Religious debates over the "Harry Potter" series of books by J. K. Rowling are based on claims that the novels contain occult or Satanic subtexts.
 A number of Protestant, Catholic, and Orthodox Christians have argued against the series, as have some Shia and Sunni Muslims.
 Supporters of the series have said that the magic in "Harry Potter" bears little resemblance to occultism, being more in the vein of fairy tales such as "Cinderella" and "Snow White", or to the works of C. S. Lewis and J. R. R. Tolkien, both of whom are known for writing fantasy novels with Christian subtexts.
 Far from promoting a particular religion, some argue, the "Harry Potter" novels go out of their way to avoid discussing religion at all.
 However, the author of the series, J. K. Rowling, describes herself as a practising Christian, and many have noted the Christian references which she includes in the final novel "Harry Potter and the Deathly Hallows".
A Very Potter Musical (originally titled Harry Potter: The Musical and often shortened to AVPM) is a musical with music and lyrics by Darren Criss and A. J. Holmes and a book by Matt Lang, Nick Lang and Brian Holden.
 The story is a parody, based on several of the "Harry Potter" novels (particularly "Harry Potter and the Philosopher's Stone", "Harry Potter and the Goblet of Fire" and "Harry Potter and the Deathly Hallows") by J. K. Rowling, as well as their film counterparts.

Question: Which writter is known to have wrote Harry Potter, Mary Gordon or J. K. Rowling?
Answer: J. K. Rowling