The Stories: "Skyjack at 22,300 Miles!", by Martin Pasko, Dick Dillin, and Frank McLaughlin(from JLA #130), "Takeover of the Earth-Masters" (from JLA #118), and "Winner Takes The Earth"(from JLA #119) both by Elliott S! Maggin, Dillin, and McLaughlin.
This was one of a series of paperback books released at the time, and heavily advertised in DC's titles. They starred Superman, Batman, Wonder Woman, The Legion of Super-Heroes, and a few others.
These are some odd books, reprinting(in the JLA's case, at least) fairly recent stories in black and white and all cut up and re-pasted to fit the paperback format. But obviously both DC and Marvel thought this was a solid new venue for their comics, since they released a number of titles in this format.
As you can see, sometimes the cutting and pasting(and, since this was pre-desktop publishing, must have been a real bitch) makes for some awkward reading, like the opening splash page:
..but in other places, the format looks quite spiffy, as in this moment, where some panels have been rejiggered and to me the look is quite pleasing, in a spot illustration kind of way:
There are no other features in this book, no special extras like DC did for the treasuries and digests. Oh well, it's still a neat little volume...
The cover is by Nick Cardy, from JLA #102. Which, ironically, is not reprinted in this book!