diff --git a/README.md b/README.md
index e2a9852..c632c79 100644
--- a/README.md
+++ b/README.md
@@ -190,11 +190,9 @@
 
 * 在线浏览
   * [MongoDB教程](http://www.w3cschool.cc/mongodb/mongodb-tutorial.html)
-* PDF版（2014.10.1）
-  * [CSDN下载](http://download.csdn.net/detail/wizardforcel/7994889)
-  * [51CTO下载](http://down.51cto.com/data/1878951)
-  * [微盘下载](http://vdisk.weibo.com/s/qybb07EH0XlB-)
-  * [百度云下载](http://pan.baidu.com/s/1bn0c8z1)
+* [PDF格式](https://www.gitbook.com/download/pdf/book/wizardforcel/w3school-mongodb)
+* [EPUB格式](https://www.gitbook.com/download/epub/book/wizardforcel/w3school-mongodb)
+* [MOBI格式](https://www.gitbook.com/download/mobi/book/wizardforcel/w3school-mongodb)
 
 ## Node.js教程