Chris Voss, a former successful FBI agent, mentioned "Getting to Yes" in his 2016 negotiation book "Never Split the Difference". He called Fisher and Ury's book "a groundbreaking treatise" and said: "I still agree with many of the powerful bargaining strategies in the book." But he criticized their methods as inadequate for hostage negotiations such as the Waco siege: "I mean, have you ever tried to devise a mutually beneficial win-win solution with a guy who thinks he's the messiah?" Voss presented alternative techniques for such situations, including "the flip side of "Getting to Yes"": getting to "no". (Bill Ury himself had written a sequel to "Getting to Yes" in 2007 titled "The Power of a Positive No".)