Die Traumdeutung.

Freud’s greatest work, the influence of which has been felt far beyond the psychiatric and medical community. Here he refined his understanding of the operation of the unconscious, interpreted dreams on the basis of wish-fulfillment theory, discussed displacement, the extensive appearance of symbols for repressed thought in conscious thought, regression, and the erotic nature of dreams. First English translation by A. A. Brill from the third German edition (New York: Macmillan, 1913). Digital facsimile of the 1900 edition from the Internet Archive at this link; of the 1913 English translation at this link.