Stanislaw Lem's fictitious criticism of nonexisting books
Stanisław Lem's fictitious criticism of nonexisting books may be found in his following works: in three collections of faux reviews of fictitious books: A Perfect Vacuum (Doskonała próżnia, 1971), Provocation (Prowokacja, 1984), and Library of 21st Century (Biblioteka XXI wieku, 1986) translated as One Human Minute, and in Imaginary Magnitude (Wielkość Urojona, 1973), a collection of introductions to nonexistent books.
Reviewing nonexistent books, a modern form of pseudepigraphy, is not a theme unique to Lem (consider Jorge Luis Borges' Pierre Menard, Author of the "Quixote" or An Examination of the Work of Herbert Quain), but the idea of an entire anthology of such pieces is rather novel. Lem attempted to create different fictional reviewers and authors for each of the books. In his own words: "I tried to imitate various styles – that of a book review, a lecture, a presentation, a speech (of a Nobel Prize laureate) and so on". Some of the reviews are lighthearted, concentrating mostly on the story; others, however, read more like serious, academic reviews. Some of the reviews are parodies, or the books being reviewed are parodies or complete impossibilities, others are quite serious and can be seen almost as drafts for novels that Lem never got around to write. It can also be said that in this book Lem criticizes the postmodernist "games for games' sake" ethos, turning it against itself.
A Perfect Vacuum 
A Perfect Vacuum (Polish: Doskonała próżnia) is a 1971 book by Polish author Stanisław Lem, the largest and best known collection of Stanislaw Lem's fictitious criticism of nonexisting books.  It was translated into English by Michael Kandel. Some of the reviews remind the reader of drafts of his science-fiction novels, some read like philosophical pieces across scientific topics, from cosmology to the pervasiveness of computers, finally others satirise and parody everything from the nouveau roman to pornography, Ulysses, "authorless writing", and Dostoevsky.
The 2008 edition of the book printed by Agora SA contained a supplement by Jacek Dukaj titled Who Wrote Stanisław Lem?, nominated for the 2009 Janusz A. Zajdel Award. It is a faux review of a book published in 2071, the book being a discussion of the activities of artificial intelligences which simulated Stanisław Lem. In fact, Dukaj maintained a column of faux reviews, Alternative Bookstore ("Księgarnia alternatywna") in Polish magazine Science Fiction (from #14 (04/2002) to #33 (12/2003)). In an interview he claimed that it was not an intended continuation of Lem's work; rather he had a number of ideas he didn't have time to develop in full.
The Agora SA edition also contained the "Glossary of Lem's Terminology" ("Słownik terminów Lemowskich") based on the book Co to są sepulki? Wszystko o Lemie (2007) by Wojciech Orliński.
Imaginary Magnitude 
In 1973 Lem published a book Imaginary Magnitude (Wielkość Urojona), a collection of introductions to books supposedly to be written in the future, in the 21st century. One of those Lem eventually developed into a book by itself: Golem XIV is a lengthy essay on the nature of intelligence, delivered by the eponymous US military computer. In 1985 it was published in English by Harvest Books under the title Imaginary Magnitude.
Imaginary Magnitude differed from the previous book, A Perfect Vacuum, by a more serious tone, and probably therefore did not enjoy the same kind of enthusiasm from the readers. 
Provocation and One Human Minute 
Provocation (Prowokacja, 1984) contains two faux reviews:
- "Provocation", for a faux book by Horst Aspernicus: Der Völkermord. I. Die Endlösung als Erlösung. II. Fremdkörper Tod, Getynga 1980
- "One Minute", for a faux book by J. Johnson and S. Johnson: One human minute, Moon Publishers, London - Mare Imbrium - New York 1985. The book is alleged to be a collection of statistical tables, a compilation that includes everything that happens to human life on the planet within any given 60 second period.
One Human Minute or Library of 21st Century (Biblioteka XXI wieku, 1986) contains three faux reviews,
- Das kreative Vernichtungsprinzip. The World as Holocaust
- Weapon Systems of The Twenty First Century or The Upside-down Evolution
- "One Minute", the same as in Provocation
- Book's entry on Lem's official page, contains author's notes in English
- Stanisław Lem, A Perfect Vacuum, Northwestern University Press, 1999, ISBN 0-8101-1733-9
- "Kiedy temat bierze pisarza za gardło", an interview with Jacek Dukaj origiginally appeared in magazine Lampa, no. 25, 04/2006
- "Apokryfy" at the official website of Stanislaw Lem
- Peter Swirski, ed. (2006). The art and science of Stanislaw Lem. McGill-Queen's Press. ISBN 0773530460.