Columbia subject headings:
Lisbon (Portugal)--Social conditions.
Poor--Portugal--Lisbon--Case studies.
Slums--Portugal--Lisbon--Case studies.
Slums--Portugal--Lisbon.
Harvard subject headings:
Lisbon (Portugal)--Social conditions.
Poor--Portugal--Lisbon--Case studies.
Slums--Portugal--Lisbon--Case studies.
Slums.
Princeton subject headings:
Lisbon (Portugal)--Social conditions.
Poor--Portugal--Lisbon--Case studies.
Slums--Portugal--Lisbon--Case studies.
Slums--Portugal--Lisbon.