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

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: (("informatic models") OR ((("informatic model") OR ("geoinformatik modelle")))).
• Removing quotes may allow a broader search: (( informatic models ) or ((( informatic model ) or ( geoinformatik modelle )))).
• Adding a wildcard symbol may retrieve word variants: (("informatic models") or ((("informatic model") or ("geoinformatik modelle"))))*.