Which head coach led the Dallas Cowboys to victory in Super Bowl XII?

Which head coach led the Oakland Raiders to victory in Super Bowl XI? In what year was Super Bowl XI played? Which team did the Dallas Cowboys defeat in Super Bowl XII? In which city was Super Bowl XII played? In what year was Super Bowl XII played? Which team did the Pittsburgh Steelers defeat in Super Bowl XIII? Who was named MVP of Super Bowl XIII? In which city was Super Bowl XIII played?