Perhaps you should try some spelling variations:
collaborative series » collaborative services, collaborative studies, collaborative agencies
collaborative social » collaborative goal, collaborative capital, collaborative cell
wetlands digital » sweetland digital, methods digital, stand digital
digital theorien » digital stories, digital rhetoric, digital terrain

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: wetlands digital theorien ((collaborative series) OR (collaborative social))~.
• Adding a wildcard symbol may retrieve word variants: wetlands digital theorien ((collaborative series) or (collaborative social))*.