On Philip K. Dick (2 essays):

Philip K. Dick’s Opus: Artifice as Refuge and Worldview  (1975, 8,060 words)
Goodbye and Hello: Differentiating within the Later P.K. Dick  (2002, 15,050 words)

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