Complex sentence: He is the author of 15 books including "Who Will Cry When You Die", "The Leader Who Had no Title", and "The Monk Who Sold His Ferrari", which has sold 3 million copies.
Split into simpler sentences: He is the author of 15 books including "Who Will Cry When You Die", "The Leader Who Had no Title". His book and "The Monk Who Sold His Ferrari" which has sold 3 million copies.