Columbia subject headings:
Le Carré, John, 1931-2020--Criticism and interpretation.
Harvard subject headings:
Espionage in literature.
Le Carré, John, 1931-2020--Criticism and interpretation.
Smiley, George (Fictitious character)
Spies in literature.
Spy stories, English--History and criticism.
Princeton subject headings:
Le Carré, John, 1931---Criticism and interpretation.