60 Minutes — Episode 40: Greg Mortenson, Howard Buffett, Novak Djokovic

You are watching the episode Greg Mortenson, Howard Buffett, Novak Djokovic An investigation into the validity of humanitarian Greg Mortenson's best-selling stories. Also: Howard Buffett, who will succeed his father, Warren Buffett, as the head of a multibillion-dollar holding company; and tennis player Novak Djokovic.