change external reference

Author: NansiYancheva

knowledge-base/dropdownlist-custom-sorting-order-groups.md

@@ -34,7 +34,7 @@ To sort the groups in a DropDownList by a custom order, perform a manual sorting
 
 1. Create a list of strings that represents the values of the group headers. This list will determine the preferred sorting order.
 2. Cast the [`DataSourceResult`]({%slug common-features-data-binding-onread%}#event-argument) to [`AggregateFunctionsGroup`](/blazor-ui/api/Telerik.DataSource.AggregateFunctionsGroup).
-3. Sort the casted data using the [`Sort` method](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1.sort?view=net-8.0) with a custom comparison function.
+3. Sort the casted data using the <a href="https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1.sort?view=net-8.0" target="_blank">`Sort` method</a> with a custom comparison function.
 4. Pass the sorted data as [`args.Data`]({%slug common-features-data-binding-onread%}#todatasourceresult-method).
 
 >caption Apply a custom grouping order in the DropDownList