Columbia subject headings:
Documentary photography--Exhibitions.
Porto (Portugal)--Politics and government--20th century--Pictorial works--Exhibitions.
Valente, Sérgio, 1942---Exhibitions.
Harvard subject headings:
Documentary photography--Exhibitions
Porto (Portugal)--Politics and government--20th century--Pictorial works--Exhibitions.
Valente, Sérgio, 1942---Exhibitions.
Princeton subject headings:
Documentary photography--Exhibitions.
Porto (Portugal)--Politics and government--20th century--Pictorial works--Exhibitions.
Valente, Sérgio, 1942---Exhibitions.