Double book with Soft Come the Dragons by Dean R. Koontz

“Cover art by Jeff Jones”

The cover art is a piece titled “Light” and appears on card #64 of the Jeffrey Jones Fantasy Art Trading Cards set, © 1993 Jeffrey Jones.

The cover of Dark of the Woods is features on page 194 of Jeffrey Jones: A Life in Art (IDW, 2010)

Jeffrey Jones: The Definitive Reference, Hill, Kolean, Maris, & Spurlock, (Vanguard, 2013)
p41: Listed as card #64 of the trading card set
p97: “DARK OF THE WOODS/SOFT COME THE DRAGONS
Dean R. Koontz
(Ace Double 13793; 1970; $0.75)
Dark of the Woods cover by Jones
(Soft Come the Dragons cover by Jack Gaughan).
PTR: Light
LIA-C full page”
p98: Small cover reproduction

This cover is featured in the book The Great American Paperback by Richard A. Lupoff (2001) on page 212 with the following caption:
”Doubled with a Koontz PBO (Soft Come the Dragons, cover by Jack Gaughan) this is one of the books that the author doesn’t particularly care to see reprinted. Koontz was a competent but unremarkable science fiction writer in his early years, then found his métier in high tension suspense and borderline horror and leaped to the bestseller list.”