Copyright 1963 by National Periodical Publications, Inc.
in Supermán (Editorial Novaro, 1952 series) #454 (julio 1, 1964)
in Showcase Presents Superman (DC, 2005 series) #4 ([September] 2008)
in Supermán (Editorial Novaro, 1952 series) #454 (julio 1, 1964)
in Superman (DC, 1939 series) #284 (February 1975)
in Supermann (Williams Forlag, 1969 series) #11/1976 ([september] 1976)
in Showcase Presents Superman (DC, 2005 series) #4 ([September] 2008)Reworked version of "The Interplanetary Olympics" in Action Comics (DC, 1938 series) #220 (September 1956). Info from Bob Bailey, 2005-03-19 (Per Sandell ed.)
Letters from readers - Paul Diamond, James Ward, Beatrice Langley, Denise Castin, Alice O'Shawn, Bruce Camden and John Romney
membership application form for the Supermen of America; also includes message in secret code (Code Jupiter No. 4)
decoded message reads: "The next issue of Action will reveal why Superman needs a secret identity."
in Supermán (Editorial Novaro, 1952 series) #454 (julio 1, 1964)
in DC Special (DC, 1968 series) #3 (April-June 1969)
in Showcase Presents: Supergirl (DC, 2007 series) #2 ([December] 2008)