"This book is very important as these archives and documents supplement China's evidence of owning the island groups in the South China Sea, and it tells the world that the Western world recognized China's sovereignty in the past," Yan Yan, the director of the Research Center for Oceans Law and Policy at the National Institute for South China Sea Studies, shared her opinions in an interview with CGTN reporter Shen Shiwei on why the book "The History and Sovereignty of South China Sea" by Anthony Carty is so essential now.