diff --git a/docs/计算机网络/topdown_ustc.en.md b/docs/计算机网络/topdown_ustc.en.md
index 6d51afe8..93759a9f 100644
--- a/docs/计算机网络/topdown_ustc.en.md
+++ b/docs/计算机网络/topdown_ustc.en.md
@@ -20,4 +20,4 @@ The recordings of the course were uploaded by Dr. Zheng himself on Bilibili. Mor
 - Course Website: <http://staff.ustc.edu.cn/~qzheng/teaching.html>
 - Recordings: <https://www.bilibili.com/video/BV1JV411t7ow/>
 - Slides: <http://staff.ustc.edu.cn/~qzheng/cn.zip>
-- Textbook: Computer Networking: A Top-Down Approach, 7th Edition
+- Textbook: _Computer Networking: A Top-Down Approach, 7th Edition_