What are your preferred books on the history of Science Fiction?

Question

Who are your preferred SF historians, deceased or living, and who do you think is at the forefront of SF literary analysis today?

Answer 1

Emannuel Carrère: I Am Alive and You Are Dead: A Journey into the Mind of Philip K. Dick

James Gunn and Matthew Candelaria, eds.: Speculations on Speculation: Theories of Science Fiction