I have read both these papers和I have read both of these pape

两个都对
both与名词、代词连用
(1)both＋(of) ＋the/ 物主代词/指示代词+名词,如：
①Both of the cats are asleep.两只猫都睡着了.
②I bought both of these bottles in China two years ago.
both of the boys=both boys =both the boys
你可以参看一下这篇文档

我告诉你，I have read both these papers意思为我读过这两个文件。I have read both of these papers意思为我读过这两种文件，
据情况用句。

后句对，应该写成I have read both of these papers. 如果用Both，只能写成I have read both papers.

后一句对。both 做代词，后边要跟介词短语。指这两张报纸纸或文章。