Article: Spielberg's film Munich, about the events following the 1972 Munich Massacre of Israeli athletes at the Olympic Games, was his second film essaying Jewish relations in the world (the first being Schindler's List). The film is based on Vengeance, a book by Canadian journalist George Jonas. It was previously adapted into the 1986 made-for-TV film Sword of Gideon. The film received strong critical praise, but underperformed at the U.S. and world box-office; it remains one of Spielberg's most controversial films to date. Munich received five Academy Awards nominations, including Best Picture, Film Editing, Original Music Score (by John Williams), Best Adapted Screenplay, and Best Director for Spielberg. It was Spielberg's sixth Best Director nomination and fifth Best Picture nomination.

Now answer this question: What book was 'Munich' based on?
Vengeance