On Philip K. Dick:
Philip K. Dick’s Opus: Artifice as Refuge and Worldview  (1975)
Goodbye and Hello: Differentiating within the Later P.K. Dick  (2002)

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 9