Columbia subject headings:
Escher, M. C. (Maurits Cornelis), 1898-1972--Exhibitions.
Harvard subject headings:
Escher, M. C. (Maurits Cornelis), 1898-1972--Exhibitions.
Exhibition catalogs.
Princeton subject headings:
Escher, M. C. (Maurits Cornelis), 1898-1972--Exhibitions.