About the book: 1968 / Strugatsky A., B. Trainees. Second Martian invasion. Stories. - M.: Young Guard, 1968. - (Library of Soviet Science Fiction). In 1968, the first “reversal book” in the USSR was published as part of the series - A. and B. Strugatsky “Trainees” and “The Second Invasion of the Martians.” There was an incident with this new product: not all readers understood the meaning of the “reversal” and returned copies to the printing house with a request to replace the “defective” book.