Got two of his books fairly cheaply from Amazon. Subterra and The Moving Fortress have that Hyperborean vibe. Jaxon’s The Secret of San Saba is fictionalized old Texas, but it has a nice Lovecraftian feel. The Conan omnibuses from Dark Horse and Marvel are also instructive. I am partial to The Conan Reader from Dark Horse which reprints The Book of Thoth miniseries. 
Just some options for people to pursue.
Thanks,
VR/Scott