Analog Science Fiction / Science Fact, April 1971 (Vol. LXXXVII, No. 2) edited by John W. Campbell, with cover art by Kelly Freas and interior illustrations by Kelly Freas and Vincent Di Fate. Fiction and non-fiction contents include: The World Menders, the conclusion of a three-part serial by Lloyd Biggle, Jr.; The Unreachable Stars, a novelette by Stanley Schmidt; Heart's Desire and Other Simple Wants, a novelette by W. Macfarlane; Higher Centers, a short story by F. Paul Wilson; Real Science for Real Problems, a science fact article by John R. Pierce; and Ecological Collapse, an editorial by John W. Campbell. Regular features include: The Analytical Laboratory; In Times to Come; The Reference Library, with book reviews by P. Schuyler Miller; and Brass Tacks, with letters from the readers.