editor: Campbell John W., Condé Nast Publications Inc., 1971
4 • Balance and Ecology • [Editorial (Analog)] • essay by John W. Campbell, Jr. [as by John W. Campbell ]8 • Zero Sum • novella by Joseph P. Martino56 • In Times to Come (Analog, July 1971) • [In Times to Come (Analog)] • essay by The Editor57 • The Man with the Anteater • [LaNague Federation] • shortstory by F. Paul Wilson66 • The Analytical Laboratory: April 1971 (Analog, July 1971) • essay by uncredited67 • Spacewar • [Science Fact (Analog)] • essay by Albert W. Kuhfeld80 • A Little Edge • novelette by William E. Cochrane [as by S. Kye Boult ]102 • The Outposter (Part 3 of 3) • serial by Gordon R. Dickson148 • Poltergeist • [Telzey Amberdon] • shortstory by James H. Schmitz163 • The Reference Library: Five from All Over (Analog, July 1971) • [The Reference Library] • essay by P. Schuyler Miller169 • Brass Tacks (Analog, July 1971) • [Brass Tacks] • essay by uncredited178 • The Lost City of Ledtintell • essay by uncredited