Question: Who wrote an unofficial sequel-series of J.K. Rowling's Harry Potter universe, that enters around the character of James Sirius Potter who makes a fleeting appearance in the  final novel  of the "Harry Potter" series, written by British author J. K. Rowling?

<P0-S0> 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. <P0-S1>  It explores the references to history, legends, and literature in J.K. Rowling's "Harry Potter" novels. <P0-S2>  Colbert conceived the idea for "The Magical Worlds of Harry Potter" while quizzing his nephew and nieces about the mythological references in the novels. <P0-S3>  He later wrote the book while teaching a seminar on self-publishing to graduate students at the University of North Carolina. <P0-S4>  The book was published in March 2001, without approval from Rowling, and has since received positive reviews from critics. <P0-S5>  An updated version of "The Magical Worlds of Harry Potter" was published in 2004 by Berkley Books. <SEP> <P1-S0> 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. <P1-S1>  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. <P1-S2>  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. <SEP> <P2-S0> The James Potter series is an unofficial sequel-series of J.K. Rowling's Harry Potter universe, written by G. Norman Lippert. <P2-S1>  The novel series centers around the character of James Sirius Potter, Harry Potter's son, a character who makes a fleeting appearance in the novel "Harry Potter and the Deathly Hallows". <P2-S2>  The series starts with his first year at Hogwarts, set one year before the end of the Harry Potter series. <SEP> <P3-S0> Harry Potter and the Deathly Hallows is the seventh and final novel of the "Harry Potter" series, written by British author J. K. Rowling. <P3-S1>  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". <P3-S2>  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. <P3-S3>  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.