Columbia subject headings:
Freytag, Gustav, 1816-1895--Criticism and interpretation--Congresses.
Freytag, Gustav, 1816-1895--Political and social views--Congresses.
Harvard subject headings:
Freytag, Gustav, 1816-1895--Criticism and interpretation--Congresses.
Freytag, Gustav, 1816-1895--Political and social views--Congresses.
Princeton subject headings:
Freytag, Gustav, 1816-1895--Criticism and interpretation--Congresses.
Freytag, Gustav, 1816-1895--Political and social views--Congresses.