'This book gathers and introduces the records of researcher Nguyen Dinh Dau written 40 years ago in many fields: geography, history, culture, art ... This is considered one of the most readable books for those who love history. Just like the name "sundry", the work is very diverse, sometimes geographically, such as discussing the Tu Long copper mine, which has an important meaning to the country in history; sometimes analyze the economic situation in the period 1512 - 1515 through a report of a Portuguese expert... In particular, many articles in the book are autobiographical, the author tells his own story associated with historical events, such as the sidelines at the Geneva Conference in 1954 or the story written in narrative in 2 days 29 and 30 April 1975...