On-sale date from copyright registration.
Inks credit confirmed from Julius Schwartz's editorial records, provided by DC Comics. The inks had been previously credited to George Roussos by DC and to Joe Giella by art spotters, though Giella denied having inked the cover in a correspondence with Bryan Stroud. Jim Shooter credit added based on an interview with Shooter by the Silver Age Sage http://www.wtv-zone.com/silverager/interviews/shooter_2.shtml.
Credits for script, pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
Page 8 is a 2/3-page.
letters submitted by Joe Arul; Leonard Rosenberg; Steven Carlberg
letters submitted by Marv Wolfman; Dennis Casey; Steve Simels
hint submitted by Terry Thomas of Bay City, Michigan