Reynolds, Richard
1992
Super Heroes: A Modern Mythology

Explores the following super heroes:

• Thor
• Superman
• Batman
• X-Men
• The Dark Knight Returns (as moment of major change in comics)
• Watchmen (caused this change together with the above)

8
From footnote 6 on p. 127:
Golden Age: 1938 – 1949
Silver Age: 1956 – around 1967/1970

118
“It is even possible that, released from the treadmill of monthly serial continuity, one or two of the most effective superhero myths might ascend the cultural ladder and become established as suitable vehicles for ‘high art’. Once could argue that, since more people now know Superman and Batman through the movies than through their regular comics, this process is already underway.”

127
Footnote 1: “Superman has been in continuous publication since 1938, Batman since 1939. Wonder woman has been in continuous publication since 1941, barring a short hiatus in 1986-87.”
Footnote 6: see p. 8