'This English language edition ... incorporates 'Lecture XLII - About Itself' and 'Afterword' which first appeared in Golem XIV' _ T.p. verso.
Originally published: San Diego : Harcourt Brace Jovanovich, 1984.
Imaginary magnitude by Stanisław Lem. ISBN 043624408X. Published by Secker & Warburg in 1985. Publication and catalogue information, links to buy online and reader comments.