Justice League of America No.29 "Crisis on Earth-Three"
Justice League of America No.30 "The Most Dangerous Earth of All"
introduced the Super Humans of Earth-Three : A world with no Super Heroes, only Super Villains.  The mysterious Crime Syndicate of Earth Three takes on both the JLA & JSA and after some initial success, end up banished in Limbo.

The Australian reprint was in Mighty No.46 - this scan is another one from the collection of Mark Cannon - Thanks Mark!  The second part of the team-up was printed Australia in All Favourites No.48.  The US reprint of this tale was in a 100 page Super Spectacular issue of JLA - it appeared in The Flash Album No.14 in Australia!!

 
Roll Call
Superman, Batman, Wonder Woman, The Flash & Green Lantern.
Dr Fate, The Hawkman, Black Canary, Dr Mid-Nite & the first Silver Age appearance of Starman.
 
Crime Syndicate
Ulta-Man, Owl Man, Superwoman, Johnny Quick & Power Ring.