Harry Turtledove collaborated with the prolific Martin H. Greenberg on three anthologies on central SF themes, looking back on the 20th century from the early years of the 21st. Book introductions by Turtledove review the theme and discuss prominent examples of novels. Story introductions are biographical.
Most reprinted authors: Poul Anderson (3), then Gregory Benford, Arthur C. Clarke, Joe Haldeman, Larry Niven, and Turtldove himself (2 each).
The Best Military Science Fiction of the 20th Century, (Ballantine Del Rey, 2001)
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The Best Alternate History Stories of the 20th Century, (Ballantine Del Rey, 2001)
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The Best Time Travel Stories of the 20th Century, Harry Turtledove & Martin H. Greenberg, eds. (Ballantine Del Rey, 2005)
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