Perhaps you should try some spelling variations:
"informatik modell" » "information modell", "informatic models", "information modelle"
"geoinformatik modelle" » "geoinformation modelle", "geoinformatic modelse", "geoinformation modellee"
"informatic model" » "informatic models", "information model", "informative model"

Try widening your search to All Fields.

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: (((("informatik modell") OR ("informatic model"))) OR ("geoinformatik modelle")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"informatik modell\") OR (\"informatic model\"))) or (\"geoinformatik modelle\"))".
• Removing quotes may allow a broader search: (((( informatik modell ) OR ( informatic model ))) or ( geoinformatik modelle )).
• Adding a wildcard symbol may retrieve word variants: (((("informatik modell") OR ("informatic model"))) or ("geoinformatik modelle"))*.