Can not open the samples. How to start developing Trados Addon? To which should I refer documents?

Can not open the samples.
How to start developing Trados Addon?
To which should I refer documents?

When open 'Sdl.Verification.Sdk.IdenticalCheck.Extended.sln' :
Message > "Sdl.Core.PluginFramework.Build.targets" not found.
can not load the project.

When open 'Sdl.Verification.Sdk.EditAndApplyChanges.MessageUI.sln',
Cannot resolve reference to 'Sdl.DesktopEditor.BasicControls'.

My Environment:
Visual Studio 2015 community
Windows 7
language>Japanese