Reprints
In the 1960s, at the height of the camp craze and the success of the Doc Savage reprints, Corinth Press (an imprint of soft porn publisher Regency) issued nine Operator 5 adventures in paperback. Their low distribution made them collector's items almost from the very first, but didn't generate enough sales to continue the series. Two later attempts were also made to reprint the stories. Currently, Wildside Press has been reprinting stories.
Read more about this topic: Operator No. 5