Volume LXXI, No. 1. Published by Conde Nast Publications, 420 Lexington Ave., New York. Editor, John W. Campbell; assistant editor, Kay Tarrant; art director, Herbert Stoltz; business manager, Robert E. Park; advertising manager, Walter J. McBride; cover artist, Nat White; illustrators, John Schoenherr and George Schelling.

Science Fact article.

Serial: part 1 of 2 parts. Illustrated by John Schoenherr. Story was expanded and published as a novel in 1963 under the title "The Earth War." Story is available as a free ebook on Project Gutenberg.

Novelette. Illustrated by George Schelling. Available as a free e-book on Project Gutenberg.

Novelette. Illustrated by George Schelling. Appeared in the anthology [i]Computer Crimes and Capers[/i], edited by Isaac Asimov, Martin H. Greenberg and Charles G. Waugh, published in 1983.

Short story. Illustrated by George Schelling. Available as a free e-book on Project Gutenberg.

Short story. Illustrated by George Schelling. Appeared in the collected works [i]Rx for Chaos[/i], published in 2009. Appeared in the anthologies [i]Analog 3[/i], edited by John W. Campbell, published in 1965; [i]A World by the Tale[/i], edited by John W. Campbell, published in 1970; and [i]The Great SF Stories #25 (1963)[/i], edited by Isaac Asimov and Martin H. Greenberg, published in 1992.

Volume LXXI, No. 1. Published by Conde Nast Publications, 420 Lexington Ave., New York. Editor, John W. Campbell; assistant editor, Kay Tarrant; art director, Herbert Stoltz; business manager, Robert E. Park; advertising manager, Walter J. McBride; cover artist, Nat White; illustrators, John Schoenherr and George Schelling.