diff --git a/How-to-make-phone-call---send-sms-with-4G-extension.md b/How-to-make-phone-call---send-sms-with-4G-extension.md
index 5c98ded..4a5043d 100644
--- a/How-to-make-phone-call---send-sms-with-4G-extension.md
+++ b/How-to-make-phone-call---send-sms-with-4G-extension.md
@@ -75,4 +75,10 @@ echo -e "Hello this is SMS message from shell\x1A" | sudo socat - /dev/ttyUSB3,c
 sleep 1
 echo -en "ATE0\r\n" | sudo socat - /dev/ttyUSB3,crnl
 ```
-replace **123456** with your really target phone number
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+replace **123456** with your really target phone number
+
+
+
+***
+
+For more AT commands, please refer the [manual](https://github.com/clockworkpi/uConsole/blob/master/SIM7500_SIM7600%20Series_AT%20Command%20Manual_V3.00.pdf)
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