Macfadden-Bartell, 19695. Mass market paperback, 2nd printing. Collection of stories from the pages of Worlds of If magazine (though the cover incorrectly states the stories are from its sister magazine, Galaxy). The Six Fingers of Time (1960) by R. A. Lafferty; Sitting Duck (1959) by Daniel F. Galouye; plus stories by Jack Sharkey, C. C. MacApp, and two others. Samuel H. Post (uncredited).