Question: Which professional basketball player won a NBA championship and spoke positively on the book "the 21 irrefutable laws of leadership"?

John Calvin Maxwell (born 1947) is an American author, speaker, and pastor who has written many books, primarily focusing on leadership.  Titles include "The 21 Irrefutable Laws of Leadership" and "The 21 Indispensable Qualities of a Leader".  His books have sold millions of copies, with some on the New York Times Best Seller List. <SEP> The 21 Irrefutable Laws of Leadership: Follow Them and People Will Follow You is a 1998 book written by John C. Maxwell and published by Thomas Nelson.  It is one of several books by Maxwell on the subject of leadership.  It is the book for which he is best-known.  The book was listed on "The New York Times" Best Seller list in April 1999 after marketing company ResultSource manipulated the list by making it look like copies of "The 21 Irrefutable Laws of Leadership" had been purchased by thousands of individuals when, in actuality, ResultSource had simply made a bulk order of the book.  The book had sold more than one million copies by 2015.  Christian businessperson John Faulkner was inspired to found Christian business magazine "TwoTen" when he read "The 21 Irrefutable Laws of Leadership".  Professional basketball player Harrison Barnes read and spoke positively of the book.  Annie Grevers of "Swimming World Magazine" wrote of Maxwell's book, "it's cheesy, but ... it did me some good".  Columnist Michael Hiltzik of the "Los Angeles Times" criticized Maxwell for including in the book "the insidious subtext ... that externalities have nothing to do with your failure", an assertion that Hiltzik argues research studies have demonstrated to be false. <SEP> Daniel Richard "Danny" Green, Jr. (born June 22, 1987) is an American professional basketball player for the San Antonio Spurs of the National Basketball Association (NBA).  He was a swingman from the University of North Carolina, where he played in more games (145) and had more wins (123) than any Tar Heel before him.  Green is also the only player in the history of the Atlantic Coast Conference (ACC) with at least 1,000 points, 500 rebounds, 250 assists, 150 three-pointers, 150 blocks and 150 steals.  He won an NCAA championship his senior year and was subsequently drafted by the Cleveland Cavaliers with the 46th overall pick in the 2009 NBA draft.  During the 2013 NBA Finals, Green set an NBA record for most three-point field goals made in a Finals series.  He then won an NBA championship with the San Antonio Spurs the following season, and became just the third player from UNC to win an NCAA championship and an NBA championship, the two others being James Worthy, and Michael Jordan.  Known for his perimeter defense and three-point shooting, Green has been a key contributor on both ends on the floor throughout his NBA career, having been selected to his first NBA All-Defensive Second Team in the 2016-17 NBA season. <SEP> Harrison Bryce Jordan Barnes (born May 30, 1992) is an American professional basketball player for the Dallas Mavericks of the National Basketball Association (NBA).  Barnes won an NBA championship with the Warriors in 2015.  He played college basketball for the North Carolina Tar Heels before being selected by the Golden State Warriors in the first round of the 2012 NBA draft with the seventh overall pick.