Columbia subject headings:
Harvard subject headings:
Knights and knighthood--Fiction.
Machine theory in literature.
Spanish literature--Classical period, 1500-1700
Spanish literature--Classical period, 1500-1700--History and criticism
Spanish literature--Classical period, 1500-1700--Themes, motives.
Princeton subject headings:
Robots in literature.
Romances--Spain.
Spanish literature--Classical period, 1500-1700.