APA (7th ed.) Citation

O'Keeffe, G. (1987). Georgia O'Keeffe, art and letters. National Gallery of Art.

Chicago Style (17th ed.) Citation

O'Keeffe, Georgia. Georgia O'Keeffe, Art and Letters. Washington: National Gallery of Art, 1987.

MLA (9th ed.) Citation

O'Keeffe, Georgia. Georgia O'Keeffe, Art and Letters. National Gallery of Art, 1987.