Superman is a copyrighted feature, appearing Action Comics magazine.
8 seconds sound clip from the The Adventures of Superman - The Baby from Krypton classic radio series.
You can hear this line at 00:11:59 in the radio play.
Quote context
[...]
- Jor-L and Lara, devoted parents of the tiny boy, perish in the giant quake that destroys Krypton.
- Remember, don't miss the next installment of Superman!
- Up in the sky look. It's a bird. It's a plane. It's Superman. (2)
- Superman is a copyrighted feature, appearing Action Comics magazine.
[...]