Columbia subject headings:
Castles--France--Midi-Pyrénées--Congresses.
Fortification--France--Midi-Pyrénées--Congresses.
Midi-Pyrénées (France)--History, Military--Congresses.
Military architecture--France--Midi-Pyrénées--History--Congresses.
Harvard subject headings:
Castles--France--Midi-Pyrénées--Congresses.
Fortification--France--Midi-Pyrénées--Congresses.
Midi-Pyrénées (France)--History, Military--Congresses.
Military architecture--France--Midi-Pyrénées--History--Congresses.
Princeton subject headings:
Castles--France--Midi-Pyrénées--Congresses.
Fortification--France--Midi-Pyrénées--Congresses.
Midi-Pyrénées (France)--History, Military--Congresses.
Military architecture--France--Midi-Pyrénées--History--Congresses.