Columbia subject headings:
Pérez Galdós, Benito, 1843-1920--Congresses.
Harvard subject headings:
Pérez Galdós, Benito, 1843-1920--Congresses.
Pérez Galdós, Benito, 1843-1920--Criticism and interpretation.
Princeton subject headings:
Pérez Galdós, Benito, 1843-1920--Criticism and interpretation--Congresses.