- Atkins, John: Arthur Koestler, 1956, Finn boken
- Braatøy, Trygve: Arthur Koestler og psykoanalysen, 1947, Finn boken
- Calder, Jenni: Chronicles of conscience : a study of George Orwell and Arthur Koestler, 1968, isbn 0-436-08120-2, Finn boken
- Levene, Mark: Arthur Koestler, 1984, isbn 0-85496-089-9, Finn boken
- Sperber, Murray A., red.: Arthur Koestler : a collection of critical essays, 1977, isbn 0-13-049205-1, Finn boken