Robert A. Heinlein, 'By His Bootstraps’, in

The Astounding-Analog Reader Book One , edited by Harry Harrison and Brian Aldiss, Sphere, London, 1973

Robert A. Heinlein, '“-All You Zombies-”’, in

The Best of Robert Heinlein 1947-59 , Sphere, London, 1973

Nick Herbert,

Faster Than Light , Plume, New York, 1988

Fred Hoyle,

October the First is Too Late , Heinemann, London, 1966

Michio Kaku,

Hyperspace , Oxford University Press, NewYork, 1994

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