Hanoi’s Institute of Sino-Nom Studies says it has lost 25 books written in traditional Vietnamese Nom script, one of which is “relevant to Vietnam’s sovereign territory,” according to the deputy head of the literature department, Nguyen Xuan Dien. When it inspected the inventory in April 2020, for the first time in over 10 years, it discovered that 29 books were missing. Among the books still unaccounted for are four written by scientist Le Quy Don and two books which record the precise geography, boundaries and borders related to Vietnam’s sovereign territory, according to Dien.