Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Van Nellefabriek' has mentioned 'Steel' in the following places:
Occurrence Sentence Text Source
[1] Soon after it was built, prominent architects described the factory as "the most beautiful spectacle of the modern age" (Le Corbusier in 1932) and "a poem in steel and glass" (Robertson in 1930).
Supported on an internal structure of reinforced concrete, the facades of the main buildings consist essentially of steel and glass, making large-scale use of the curtain wall principle.