Originally Posted by carandol
The first four, written between 1958 and 1963, (The Time Traders, Galactic Derelict, The Defiant Agents, and Key Out of Time) are all available as free ebooks from www.feedbooks.com
. The volume available at Baen as "Time Traders" is actually the first two of those books.
Baen also have "Time Traders II" which contains "The Defiant Agents" and "Key Out of Time".