Liechtensteinische Landesbibliotek - The national library and archives of Liechtenstein. A lot of the studies and full articles about Liechtenstein's history are offered as free pdf downloads. Thoroughly recommended, though a basic grasp of German is needed while searching for things on the site.

The Official Tourism Site of Liechtenstein (English language version) - Outside of various tourist information, a good resource on the geography of the country and its historical and natural landmarks.

Liechtenstein

List of Resources by Country and Region

Liechtenstein Timelines and Scenarios

Liechtenstein Points of Divergence