The research, he says revealing this for the first time, involves San Francisco in 1969 and the Supernatural episode "In the Beginning." I've mentioned a few times that Heart of the Dragon takes place in three different time periods. Those three are December 1969, December 1989, and December 2009, and the first of those will involve the Campbell family: Samuel and Deanna and their daughter Mary, as seen in the aforementioned episode. (The 1989 part will involve John Winchester.)
I'll get back to that on Monday, however, as the weekend belongs to Farscape. The next two days -- when I'm not at karate (today) or beach training and hanging out at Jones Beach (tomorrow) -- will be spent writing the script for D'Argo's Quest #1.