Columbia subject headings:
Harvard subject headings:
Architecture--Portugal--Loulé--Congresses.
Mina De Sal-Gema (Loulé, Portugal)--Congresses.
Salt mines and mining--Portugal--Loulé--Congresses.
Underground architecture--Portugal--Loulé--Congresses.
Urban renewal--Portugal--Loulé--Congresses.
Princeton subject headings:
Architecture--Portugal--Loulé--Congresses.
Mina De Sal-Gema (Loulé, Portugal)--Congresses.
Salt mines and mining--Portugal--Loulé--Congresses.
Underground architecture--Portugal--Loulé--Congresses.
Urban renewal--Portugal--Loulé--Congresses.