Letters page contains the pre-yellow sun theory of Superboy/man's x-ray, and other vision powers. Caused by differences in Earth's atmosphere from Krypton's.
in The Greatest 1950s Stories Ever Told (DC, 1992 series) #[nn] (1992) [cover illustration]inside cover
in Superboy (DC, 1949 series) #174 (June 1971)
in 80 Page Giant (DC, 1964 series) #G83 (May-June 1971)
in Superman (Egmont Ehapa, 1966 series) #26/1972 (23. Dezember 1972)Proto-Red Kryptonite story.
from World's Finest Comics (DC, 1941 series) #66 (September-October 1953)
in The Aquaman Archives (DC, 2003 series) #1 ([January] 2003)
in Showcase Presents Aquaman (DC, 2007 series) #1 ([February] 2007)Writer credit from Martin O'Hearn at http://martinohearn.blogspot.com/ .
in World's Finest Comics (DC, 1941 series) #188 (October-November 1969)
in 80 Page Giant (DC, 1964 series) #G64 (October-November 1969)
in DC Special Blue Ribbon Digest (DC, 1980 series) #9 (May 1981)
in Showcase Presents Green Arrow (DC, 2006 series) #1 ([January] 2006)Origin: Speedy (of Earth-One)
from Action Comics (DC, 1938 series) #199 (December 1954)