Probably Bolton's best-known work, at least early on, was his Marada series in EPIC ILLUSTRATED 10-12 (black and white), and later 22-23 (in color), for Marvel.
It began as a Red Sonja series, and because of copyright problems evolved into a creator owned series.

EPIC 10-12 were later reprinted as a MARADA graphic novel in 1984, with color added in the stories.