diff --git a/README.md b/README.md
index d41522a..6b1547c 100644
--- a/README.md
+++ b/README.md
@@ -37,9 +37,11 @@ docker run -it --rm chronolaw/cpp_study
 
 * [Bjarne Stroustrup's FAQ](http://www.stroustrup.com/bs_faq.html)
 * [Bjarne Stroustrup's C++11 FAQ](http://www.stroustrup.com/C++11FAQ.html)
+* [Bjarne Stroustrup's C++ HOPL4 (zh-cn)](https://github.com/Cpp-Club/Cxx_HOPL4_zh)
 * [C++ Core Guidelines](https://github.com/isocpp/CppCoreGuidelines)
 * [OpenResty Code Style Guide(zh-cn)](http://openresty.org/cn/c-coding-style-guide.html)
 * [Google Code Style Guide](https://google.github.io/styleguide/cppguide.html)
+* [ProtoBuffer C++ Doc](https://developers.google.com/protocol-buffers/docs/reference/cpp-generated)
 
 
 ## Dev Links
diff --git a/section1/oop.cpp b/section1/oop.cpp
index dece5a1..9ad4968 100644
--- a/section1/oop.cpp
+++ b/section1/oop.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2050 by Chrono
+// Copyright (c) 2020 by Chrono
 //
 // g++ oop.cpp -std=c++11 -o a.out;./a.out
 // g++ oop.cpp -std=c++14 -o a.out;./a.out
@@ -9,6 +9,10 @@
 #include <vector>
 #include <set>
 
+#if(defined (__MINGW64__) || (defined __MINGW32__))
+#include <cstdint>
+#endif
+
 #if 1
 
 class Interface {};
diff --git a/section1/preprocess.cpp b/section1/preprocess.cpp
index bbf19f3..20c6c35 100644
--- a/section1/preprocess.cpp
+++ b/section1/preprocess.cpp
@@ -26,6 +26,8 @@ void case1()
 #
 #if __linux__
 #   define HAS_LINUX    1
+#else
+#   define HAS_LINUX    0
 #endif
 #
     cout << "linux is " << HAS_LINUX << endl;