Update regex.rst

source/additional_information/regex.rst

@@ -46,3 +46,8 @@ Regular Expressions
 * **Dial 9 then Ten digits:** ^9(\\d{10})$
 * **Dial 9 then Eleven digits:** ^9(\\d{11})$
 * **Dial 9 then International:** ^9(\\d{12,20})$
+
+**Links**
+https://regex101.com/
+https://regex101.com/r/QmOZiH/3/
+