Eight-year-old Phung Xuan Vu and his 10-year-old brother were responsible for fetching food for their family, which was in the constant grip of hunger. They were living in Vietnam in the 1980, so this required ration cards. One of the family's most important possessions was a booklet of vouchers for food. As the older child, Vu's brother took care of the booklet, knowing that if he lost it, the family would have nothing to eat. The vouchers inside were printed on waxy yellow tissue paper. They meant the difference between going hungry and having something to eat, although it was...