Perhaps you should try some spelling variations:
transport resources » transport research, transport measures
free transport » green transport, sea transport, freight transport
resources case » resources chapter
based transfer » based transfers, basin transfer, basin transfers
language co » language code, language csl, language _
cerda und » cea und, ceuta und, coda und
und free » und freie, und frei, und fremde
co based » cco based, cov based, vco based

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( cerda und free transport resources case ) OR ( language co based transfer _ coda ))~.
• Adding a wildcard symbol may retrieve word variants: (( cerda und free transport resources case ) or ( language co based transfer _ coda ))*.