diff --git a/README.md b/README.md
index 636b263..e07b1fc 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@
 - [六、附录](doc/6_appendix.md)
   - [6.1 更多 Linux 工具](doc/6.1_Linuxtools.md)
   - [6.2 更多 Windows 工具](doc/6.2_wintools.md)
-  - [6.3 博客、文章和书籍](doc/6.3_books&blogs.md)
+  - [6.3 更多资源](doc/6.3_books&blogs.md)
   - [6.4 习题 write-up](doc/6.4_writeup.md)
   - [6.5 Linux x86-64 系统调用表](doc/6.5_syscall.md)
 
diff --git a/SUMMARY.md b/SUMMARY.md
index ab339a6..c2289cd 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -53,6 +53,6 @@
 * [六、附录](doc/6_appendix.md)
     * [6.1 更多 Linux 工具](doc/6.1_Linuxtools.md)
     * [6.2 更多 Windows 工具](doc/6.2_wintools.md)
-    * [6.3 博客、文章和书籍](doc/6.3_books&blogs.md)
+    * [6.3 更多资源](doc/6.3_books&blogs.md)
     * [6.4 习题 write-up](doc/6.4_writeup.md)
     * [6.5 Linux x86-64 系统调用表](doc/6.5_syscall.md)
diff --git a/doc/3.3.1_format_string.md b/doc/3.3.1_format_string.md
index 0af2e82..0daee39 100644
--- a/doc/3.3.1_format_string.md
+++ b/doc/3.3.1_format_string.md
@@ -268,12 +268,23 @@ Hello 32 f7f95580 565555f4 !
 通过提供和格式字符串，我们就能够控制格式化函数的行为。漏洞的利用主要有下面几种。
 
 #### 使程序崩溃
+格式话字符串漏洞通常要在程序崩溃时才会被发现，所以利用格式化字符串漏洞最简单的方式就是使进程崩溃。在 Linux 中，存取无效的指针会引起进程收到 `SIGSEGV` 信号，从而使程序非正常终止并产生核心转储（在 Linux 基础的章节中详细介绍了核心转储）。我们知道核心转储中存储了程序崩溃时的许多重要信息，这些信息正是攻击者所需要的。
+
+利用类似下面的格式字符串即可触发漏洞：
+```c
+printf("%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s")
+```
+- 对于每一个 `%s`，`printf()` 都要从栈中获取一个数字，把该数字视为一个地址，然后打印出地址指向的内存内容，直到出现一个 NULL 字符。
+- 因为不可能获取的每一个数字都是地址，数字所对应的内存可能并不存在。
+- 还有可能获得的数字确实是一个地址，但是该地址是被保护的。
+
+#### 查看栈内容
+使程序崩溃只是验证漏洞的第一步，攻击者还可以利用格式化输出函数来获得内存的内容，为下一步漏洞利用做准备。
 
-#### 查看栈
 
 #### 查看任意地址的内存
 
-#### 覆盖栈
+#### 覆盖栈内容
 
 #### 覆盖任意地址内存
 
diff --git a/doc/6.3_books&blogs.md b/doc/6.3_books&blogs.md
index d05b433..c720e70 100644
--- a/doc/6.3_books&blogs.md
+++ b/doc/6.3_books&blogs.md
@@ -1,33 +1,46 @@
-# 网站、文章和书籍
+# 更多资源
 
-- [网站](#网站)
+- [课程](#课程)
+- [站点](#站点)
 - [文章](#文章)
 - [书籍](#书籍)
 
 
-## 网站
+## 课程
+- [Intro to Computer Systems, Summer 2017](https://www.cs.cmu.edu/~213/schedule.html)
+- [Modern Binary Exploitation Spring 2015](http://security.cs.rpi.edu/courses/binexp-spring2015/)
 - [OpenSecurityTraining](http://opensecuritytraining.info/Welcome.html)
-- [sec-wiki](https://www.sec-wiki.com/)
 - [Stanford Computer Security Laboratory](http://seclab.stanford.edu/)
+- [CS642 Fall 2014: Computer Security](http://pages.cs.wisc.edu/~rist/642-fall-2014/)
+- [Offensive Computer Security Spring 2014](http://www.cs.fsu.edu/~redwood/OffensiveComputerSecurity/)
+- [System Security and Binary Code Analysis](http://www.utdallas.edu/~zhiqiang.lin/spring2012.html#toc7)
+- [SATSMT Summer School 2011](https://wikis.mit.edu/confluence/display/satsmtschool11/SATSMT+Summer+School+2011;jsessionid=994854C69CABD6B1DC53F381A3CFF5E8)
+- [CS 161 : Computer Security Spring 2017](https://www.icir.org/vern/cs161-sp17/)
+- [Introduction to Computer Security Fall 2015](https://users.ece.cmu.edu/~dbrumley/courses/18487-f15/#lectures)
+
+
+## 站点
+- [sec-wiki](https://www.sec-wiki.com/)
 - [Shellcodes database for study cases](http://shell-storm.org/shellcode/)
 - [Corelan Team Articles](https://www.corelan.be/index.php/articles/)
+- [LOW-LEVEL ATTACKS AND DEFENSES](http://www.cs.umd.edu/class/spring2014/cmsc838g/list.txt)
+- [FuzzySecurity](https://www.fuzzysecurity.com/tutorials.html)
+- [LiveOverflow](http://liveoverflow.com/index.html)
+
+
+## 文章
 - [Debugging Fundamentals for Exploit Development](http://resources.infosecinstitute.com/debugging-fundamentals-for-exploit-development/)
-- [Tricks for Exploit Development](http://resources.infosecinstitute.com/in-depth-seh-exploit-writing-tutorial-using-ollydbg/)
 - [Introduction to return oriented programming (ROP)](http://codearcana.com/posts/2013/05/28/introduction-to-return-oriented-programming-rop.html)
 - [Smashing The Stack For Fun And Profit](http://insecure.org/stf/smashstack.html)
 - [Understanding DEP as a mitigation technology part 1](https://blogs.technet.microsoft.com/srd/2009/06/12/understanding-dep-as-a-mitigation-technology-part-1/)
+- [Tricks for Exploit Development](http://resources.infosecinstitute.com/in-depth-seh-exploit-writing-tutorial-using-ollydbg/)
 - [Preventing the Exploitation of Structured Exception Handler (SEH) Overwrites with SEHOP](https://blogs.technet.microsoft.com/srd/2009/02/02/preventing-the-exploitation-of-structured-exception-handler-seh-overwrites-with-sehop/)
-- [CS642 Fall 2014: Computer Security](http://pages.cs.wisc.edu/~rist/642-fall-2014/)
-- [Offensive Computer Security Spring 2014](http://www.cs.fsu.edu/~redwood/OffensiveComputerSecurity/)
 - [From 0x90 to 0x4c454554, a journey into exploitation.](http://www.myne-us.com/2010/08/from-0x90-to-0x4c454554-journey-into.html)
-- [Software Modeling and Verification](http://www.myne-us.com/2010/08/from-0x90-to-0x4c454554-journey-into.html)
-- [SATSMT Summer School 2011](https://wikis.mit.edu/confluence/display/satsmtschool11/SATSMT+Summer+School+2011;jsessionid=994854C69CABD6B1DC53F381A3CFF5E8)
-- [LOW-LEVEL ATTACKS AND DEFENSES](http://www.cs.umd.edu/class/spring2014/cmsc838g/list.txt)
 - [Checking the boundaries of static analysis](https://docs.google.com/presentation/d/1_Te02rSqn7wuhsmkkluqWhDBoXXFVUL5Mp0dUxH0cVE/edit#slide=id.gbd819d83_120)
-- [Reference Library](https://moflow.org/#%5B%5BReference%20Library%5D%5D)
 - [Deep Wizardry: Stack Unwinding](http://blog.reverberate.org/2013/05/deep-wizardry-stack-unwinding.html)
+- [Linux (x86) Exploit Development Series](https://sploitfun.wordpress.com/2015/06/26/linux-x86-exploit-development-tutorial-series/)
+- [Hack The Virtual Memory](https://blog.holbertonschool.com/hack-the-virtual-memory-c-strings-proc/#)
 
-## 文章
 
 ## 书籍
 - [Hacking: The Art of Exploitation, 2nd Edition by Jon Erickson](https://leaksource.files.wordpress.com/2014/08/hacking-the-art-of-exploitation.pdf)
diff --git a/doc/6_appendix.md b/doc/6_appendix.md
index 588c7ad..b69bd0e 100644
--- a/doc/6_appendix.md
+++ b/doc/6_appendix.md
@@ -2,6 +2,6 @@
 
 - [6.1 更多 Linux 工具](6.1_Linuxtools.md)
 - [6.2 更多 Windows 工具](6.2_wintools.md)
-- [6.3 博客、文章和书籍](6.3_books&blogs.md)
+- [6.3 更多资源](6.3_books&blogs.md)
 - [6.4 习题 write-up](6.4_writeup.md)
 - [6.5 Linux x86-64 系统调用表](http://blog.rchapman.org/posts/Linux_System_Call_Table_for_x86_64/)