Perhaps you should try some spelling variations:
perspectives cross » perspectives across, perspectives book
perspective based » perspective case
commercial class » commercial cases, commercial crisis, commercial crops
class taiwan » class thailand, law taiwan, atlas taiwan
taiwan based » tail based, taiwan kate, taiwan lived

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: commercial class taiwan based ((perspectives cross) or (perspective based)) studies.~.
• If you are trying to use Boolean operators, they must be ALL CAPS: commercial class taiwan based ((perspectives cross) OR (perspective based)) studies..
• Adding a wildcard symbol may retrieve word variants: commercial class taiwan based ((perspectives cross) or (perspective based)) studies.*.