Columbia subject headings:
Harvard subject headings:
Aisne (France)--Antiquities.
Aisne (France)--History.
Underground architecture--France--Aisne.
Underground construction
Princeton subject headings:
Aisne (France)--Antiquities.
Aisne (France)--History.
Excavations (Archaeology)--France--Aisne.
Souterrains--France--Aisne.
Underground architecture--France--Aisne.