Most papers won’t cite the specific version (2.4), but rather generally.

Microsoft. (2020). Microsoft.UI.Xaml (Version 2.4) [Computer software]. https://www.nuget.org/packages/Microsoft.UI.Xaml/2.4.0

Microsoft.UI.Xaml is a UI framework used for building Windows 10 and Windows 11 applications, particularly those using the Universal Windows Platform (UWP). Version 2.4 of Microsoft.UI.Xaml is a specific release that provides a set of managed APIs for building modern, user-friendly applications.

for a paper

Key details:

| Namespace | Class | Change | | --- | --- | --- | | Microsoft.UI.Xaml.Controls | TreeView | Added | | Microsoft.UI.Xaml.Controls | TreeViewItem | Added | | Microsoft.UI.Xaml.Core | TreeViewList | Added |