Here are some examples of subject headings that can be used when searching for books on world religions in Duke's library catalog or in other library catalogs via WorldCat. Your specific information needs might change the terms you want to use, but these may provide a good start. Use the facets on the left hand side of the search results page to further refine results.
|Sufism||Japan -- Religion (or Shinto)|
|Religion (general material on religion)||Religions (focus on world religions)|