'This book gathered a total of 25 articles & papers (that were called by the author miscellaneous remarks and never published before) covering many different aspects of Vietnam history and geography that written some decades ago by the research Nguyen Dinh Dau. Here are some writings from the book: 1 - Vietnam copper mine of Tu Long was lost by France colonialism. 2 - Vietnam economic situation in the years of 1512 - 1515 by the report of Tome Pires. 3 - Quang Nam land and the creation of Vietnam modern written language. 4 - Hypotheses on place name of Sai Gon. 5 - The maps of Hong Duc and Alexandre de Rhodes and Pulo Sisi. 6 - Understanding the units of measures of Vietnam in the past. 7 - Currency in Sai Gon in the years of 1859 - 1954. 8 - The report of the insider about the days of 29 & 30th April, 1975.