Lewis Carroll Epstein,

Relativity Visualised , Insight Press, San Francisco, 1987

David Gerrold,

The Man Who Folded Himself , Faber, London, 1973

Richard Gott,

Time Travel in Einstein’s Universe , Houghton Mifflin, Boston, 2001

Joe Haldeman,

The Forever War , Orbit, London, 1976

Harry Harrison,

Technicolor Time Machine , Orbit, London, 1976

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