http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Khám phá những bí ẩn về lịch sử nhân loại như: bí ẩn văn hoá cổ đại và bí ẩn về các nhân vật lịch sử
World history,Mystery,Lịch sử thế giới,Điều bí ẩn