primary source 等於最原始既文件, 不包含試圖解讀另一部著作既成份
secondary source 等於分析primary 既文件
比如說(1)通勝河圖洛書係primary source, 而麥玲玲出書試圖分析通勝就係secondary source
(2) 毛語錄係primary source, 而批評和讚美毛語錄既文章=secondary source.
如果你寫paper, 一般只可以引用primary source, 唔可以用secondary source
treaty terms 係primary.