Historical evidence of Vietnam's sovereignty over Hoang Sa (Paracel) and Truong Sa (Spratly) archipelagoes are featured is a book that Dr. Han Nguyen Nguyen Nha has devoted a great deal of effort, according to radio the Voice of Vietnam.

Professor Phan Huy Le, Chairman of the Vietnam History Science Association said since 1974 after the Hoang Sa Archipelago controlled by the then Saigon administration, was invaded by China, Dr. Han Nguyen Nguyen Nha became much interested in this topic.

"In recent years, Dr. Nha has written many articles about Vietnam's sovereignty over the two archipelagoes of Hoang Sa and Truong Sa and attended many domestic and international seminars on the East Sea. Dr. Han Nguyen Nguyen Nha is one of the Vietnamese leading experts on Hoang Sa-Truong Sa with nearly 40 years of East Sea research experience "Prof. Phan Huy Le said.

Works on historical evidence of Vietnam's sovereignty over the Hoang Sa and Truong Sa archipelagoes published by the Vietnam Education Publishing House are a dedicated research and collection by the author over the past 40 years based on his PhD thesis in 2003 and updated study results.

Plentiful and diverse documents of the author’s research come from not only the Vietnamese people but also from Western and Chinese people. Systematic study of Han–Nom documents before 1909 - the year began to witness sovereignty dispute over Hoang Sa Archipelago, include official administrative documents adopted by kings under the Nguyen dynasty.

By introducing monographic books, and administrative maps and domestic and foreign documents related to the Hoang Sa and Truong Sa archipelagoes to date, the author has helped readers gain a better understanding of the process of discovery, actual ownership, exercise of power by managing executive work and sending teams to Hoang Sa to conduct annual surveys and engage in hydraulic measurement, mapping, mining, exploiting natural resources, building temples, planting markers and steles and growing trees.

These are seen as a symbol of Vietnam’s sovereignty over Hoang Sa and Truong Sa through different periods. The author’s research methodology strictly adheres to objectivity, respecting historical truth and honoring valuable historical documents that no country can possess.

These historical documents demonstrate the will and mettle of many Vietnamese generations - the first owners who discovered and actually owned the Hoang Sa and Truong Sa archipelagoes. These documents also proved that the Vietnamese State, through successive periods, affirmed its sovereignty and enforcement of administrative management of Hoang Sa and Truong Sa archipelagoes for hundreds of years. Dating back from 1909, no country filed a claim over sovereignty dispute.

According to Professor Phan Huy Le, Dr. Nguyen Nha has painstakingly collected related historical and legal materials such as the official documents of the Nguyen Dynasty and those on sovereignty enforcement of the Tay Son, Nguyen Dynasty and French administrations from ancient bibliographic treasures of Vietnam, China and western nations.

The author has also collected Chinese materials and old maps to prove that before 1909, China never regarded Hoang Sa and Truong Sa archipelagoes as territory of their own. "By systematically analysing these documents, the author has given sound scientific and legal evidence to affirm Vietnam's sovereignty over the two archipelagoes. Dr. Nguyen Nha’s research works are his made tremendous contribution to the country’s history," Prof. Phan Huy Le noted.

Through his book about evidence of Vietnam's sovereignty over the Hoang Sa and Truong Sa archipelagoes, readers can more clearly understand the nation’s sovereignty over the two islands had long been established which is a historical truth in line with international law.

Dr. Nguyen Nha said he hopes his book will give Vietnamese teachers and students an insight into Vietnam's sovereignty over the two islands, thus helping encourage the people in all walk of life promote the nation’s historical truth and persist with their struggle for national sovereignty and territorial integrity. “Defending the Truong Sa and Hoang Sa islands is a vivid manifestation of patriotism spirit of generations of Vietnamese people who should join hands to build a mighty nation. By doing so, we can reach the goal of safeguarding national sovereignty and developing Vietnam into a nation strong in the marine-based economy”, Nha added.-VNA