Author Truong Quoc Dung (1797 - 1864), a mandarin under three Nguyen kings: Thieu Tri, Minh Menh, Tu Duc. His life as a mandarin sometimes went up and down, but his contributions could not be denied. Thoai Thuc Ky Van is a synthesis of half research, half autograph, recording many facts, classified into the following categories: Geography: talking about the changes of rivers, mountains and roads from the Hung Vuong period to the Minh Mang period. There are records on Cambodia, Siam and Burma ...; Regimes: about officials, benefits, faculty (literature), military forces, taxes, currency, public land ... from the Ly dynasty to the Minh Mang period; Dignity: tells stories of studies and historical figures from the Tran to Minh Mang dynasties; Fairy: Most talk about communal houses, temples, pagodas, citadels, ... in Central and Northern Vietnam; Strange story: Record myths related to Vietnamese historical figures...