Perhaps you should try some spelling variations:
transformer based » transformer les, transport based, transformation based
ray transformer » a transformer, tape transformer, _ transformer
based across » based access, shared across, varied across
den transfer » gene transfer, heat transfer, data transfer
luis a » luis f, luis c
a den » _ den, a der, a des
rene » rent, gene

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( luis rene ray transformer based across ) or ( luis a den transfer _ cao ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( luis rene ray transformer based across ) OR ( luis a den transfer _ cao )).
• Adding a wildcard symbol may retrieve word variants: (( luis rene ray transformer based across ) or ( luis a den transfer _ cao ))*.