To search for books (and articles) with horror as a subject, try searching: "su:horror" in UNB WorldCat below.
To narrow your focus, try general keyword searching using relevan terms. For example:
gothic horror
american gothic
gothic spiritualism
horror asia
horror korea
horror gaming
Downloading e-books for offline reading with Adobe Editions (applies to EBSCO and ebrary content):
https://youtu.be/s-aE4x344aw