In what year was Super Bowl XVII played?

Which team did the Washington Redskins defeat in Super Bowl XVII? John Riggins was named MVP of which Super Bowl? In which city was Super Bowl XVII played? Which head coach led the Washington Redskins to victory in Super Bowl XVII? Which team did the Los Angeles Raiders defeat in Super Bowl XVIII? Marcus Allen was named MVP of which Super Bowl? In which city was Super Bowl XVIII played? Which head coach led the Los Angeles Raiders to victory in Super Bowl XVIII?