diff --git a/README.md b/README.md
index 3ad8b4a..40b1bd4 100644
--- a/README.md
+++ b/README.md
@@ -3265,7 +3265,7 @@ int main( void )
 
 <b><details><summary>📚 书籍</summary></b>
 
-> [huihut/CS-Books](https://github.com/huihut/CS-Books)：📚 Computer Science Books 计算机技术类书籍
+> [huihut/CS-Books](https://github.com/huihut/CS-Books)：📚 Computer Science Books 计算机技术类书籍 PDF
 
 ### 语言
 
diff --git a/README_Details.md b/README_Details.md
index 1bc2aee..229f01d 100644
--- a/README_Details.md
+++ b/README_Details.md
@@ -3260,7 +3260,7 @@ int main( void )
 
 ## 📚 书籍
 
-> [huihut/CS-Books](https://github.com/huihut/CS-Books)：📚 Computer Science Books 计算机技术类书籍
+> [huihut/CS-Books](https://github.com/huihut/CS-Books)：📚 Computer Science Books 计算机技术类书籍 PDF
 
 ### 语言