ON THE STRUGATSKY BROTHERS:
The SF Opus of the Strugatsky Brothers  (1974-81 and 1990)
An E-Mail to Russia  (2003)

D. Suvin, Parables of Freedom and Narrative Logics: Positions and Presuppositions in Science Fiction and Utopianism, 2 Vols. Ed. Eric D. Smith. Oxford: P. Lang, 2021.
chapter 11