This is Giant Superman 18, published by Mimosa (SA Magazine Co) +/- 1963-1964.
It reprints the cover and both stories from DC Comics' Adventure Comics 284 (1961):
"Clark Kent goes to Reform School"
Aquaman: "The Charge of Aquaman's Sea Soldiers"
Also reprinted is this story from DC Comics' Action Comics 273 (1961):
"The Supergirl of Two Worlds"
Also reprinted is this story from DC Comics' Action Comics 220 (1956):
Tommy Tomorrow: "The Flying Dutchman of Space"
48pages, glossy colour cover, black and white newsprint interior.
Here is the cover of issue 18 and DC Comics' original cover: