title: God Is Not Great
context: God Is Not Great is a 2007 book by Anglo-American author and journalist Christopher Hitchens, in which he makes a case against organized religion. It was originally published in the United Kingdom by Atlantic Books as God Is Not Great: The Case Against Religion and in the United States by Twelve as God Is Not Great: How Religion Poisons Everything, but was republished by Atlantic Books in 2017 with no subtitle.
question: What was the best selling book Hitchens published?
answers: 2007