Columbia subject headings:
Constructivism (Philosophy)
Vienna (Austria)--Intellectual life--20th century.
Vienna circle.
Von Foerster, Heinz, 1911-2002.
Harvard subject headings:
Constructivism (Philosophy)
Vienna (Austria)--Intellectual life--20th century.
Vienna circle.
Von Foerster, Heinz, 1911-2002.
Princeton subject headings:
Constructivism (Philosophy)
Vienna (Austria)--Intellectual life--20th century.
Vienna circle.
Von Foerster, Heinz, 1911-2002.