As far as undisclosed sources go, Hubbard's work with Jack Parsons was not known at the time, as that was yet another person Hubbard scammed. Hubbard's only ack

As far as undisclosed sources go, Hubbard's work with Jack Parsons was not known at the time, as that was yet another person Hubbard scammed. Hubbard's only acknowledgment of that time was a highly fictionalized account of breaking up a circle of black magicians.