diff --git a/readme.md b/readme.md
index f30283c..df06014 100644
--- a/readme.md
+++ b/readme.md
@@ -538,8 +538,6 @@ typedef struct {
 ## 📚 参考资料
 
 - [STM32F103 参考手册](https://www.st.com/resource/en/reference_manual/rm0008-stm32f101xx-stm32f102xx-stm32f103xx-stm32f105xx-and-stm32f107xx-advanced-armbased-32bit-mcus-stmicroelectronics.pdf)
-- [Modbus RTU 协议规范](https://modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf)
-- [UC1698U 数据手册](https://www.ultrachip.com.cn/)
 
 ## 🔄 版本历史