Before I was a Robert Anton Wilson fan, I was a Philip Jose Farmer fan. Farmer was a prolific and energetic science fiction writer with a wide variety of interests.
I knew that RAW was a fan of Farmer's work because Erie Wagner says so in his book, but I didn't realize the two writers had written about each other until I ran across this article on the essential Rawilsonfans.com web site. I was happy to read that Wilson liked the Riverworld series.
Other key Farmer works include the World of Tiers books and Hugo Award winning novella, "Riders of the Purple Wage," which refers to Finnegans Wake.