The New tradition :
modern Americans before 1940 : April 27 through June 2, 1963.

APA Citation

Corcoran Gallery of Art. (1963). The New tradition: modern Americans before 1940 : April 27 through June 2, 1963. Washington, D.C.: Corcoran Gallery of Art.

MLA Citation

Corcoran Gallery of Art. The New Tradition: Modern Americans Before 1940 : April 27 Through June 2, 1963. Washington, D.C.: Corcoran Gallery of Art, 1963.

Warning: These citations may not always be complete (especially for serials).