Columbia subject headings:
Castles--Liechtenstein--Guidebooks.
Castles--Switzerland--Guidebooks.
Liechtenstein--Description and travel.
Switzerland--Description and travel.
Harvard subject headings:
Castles--Liechtenstein--Guidebooks.
Castles--Switzerland--Guidebooks.
Liechtenstein--Guidebooks.
Switzerland--Guidebooks
Princeton subject headings:
Castles--Liechtenstein--Guidebooks.
Castles--Switzerland--Guidebooks.
Liechtenstein--Description and travel.
Switzerland--Description and travel.