diff --git a/en/image-quality-tuning.md b/en/image-quality-tuning.md
index e7a5270..bda9ab2 100644
--- a/en/image-quality-tuning.md
+++ b/en/image-quality-tuning.md
@@ -55,8 +55,7 @@ Download [PQTools][pqt] and extract a zip archive somewhere on your PC.
 Launch `HiPQTools.exe`, select `Hi3516EV200_V1.0.1.2`, type IP address of your
 camera and click `OK`.
 
-Use [this manual][man] as a reference.
 
 [mcr]: https://ssd.mathworks.com/supportfiles/MCR_Runtime/R2012a/MCR_R2012a_win32_installer.exe
 [pqt]: https://openipc.org/utilities
-[man]: https://drive.google.com/file/d/1mY1lXMZVNz2Ia5CPvTF-K-907eIioSYU/view?usp=sharing
+