Columbia subject headings:
Architecture, Roman--Italy--Phlegraean Plain--Guidebooks.
Phlegraean Plain (Italy)--Antiquities--Guidebooks.
Harvard subject headings:
Architecture, Roman--Italy--Phlegraean Plain--Guidebooks.
Phlegraean Plain (Italy)--Antiquities--Guidebooks.
Princeton subject headings:
Architecture, Ancient--Italy--Phlegraean Plain.
Phlegraean Plain (Italy)--Antiquities.
Phlegraean Plain (Italy)--Description and travel.