The Letters of Sigmund Freud (1960), edited by Ernst L. Freud, presents a selection of Sigmund Freud’s extensive correspondence with family, friends, and colleagues.

In The Ego and the Id (1923), Freud expands on his essential theory concerning the basic structure of the human psyche, which consists of the id, the ego, and the superego.

Dreams (1974) is a compilation of Carl Jung’s essays on dream psychology.

Sigmund Freud: His Life in Pictures and Words (1978), edited by Ernst Freud, Lucie Freud, and Ilse Grubrich-Simitis, features numerous photographs from Freud’s life along with a biographical sketch by K. R. Eissler.

In The Interpretation of Dreams: Freud’s Theories Revisited (1987), Laurence M. Porter examines critical reactions to Freud’s dream analysis theories, considering advancements in dream psychology through the late twentieth century.

Freud: A Life for Our Times (1988) is a renowned biography of Freud by Peter Gay, who has authored several works on Freud’s life and contributions.

Freud’s Five Lectures on Psycho-Analysis (1989), originally published in 1910, is one of his pivotal texts. Here, he articulates the foundational aspects of his psychoanalytic theory. The 1989 edition, edited by James Strachey, includes a biographical introduction by Peter Gay.

In A Primer of Freudian Psychology (1999), Calvin S. Hall offers an introductory overview of the main concepts in Freudian theory.