Perhaps you should try some spelling variations:
functionalanalysis%22 » funktionalanalysis%22, functionalanalytic%22, functionaalanalyse%22
funktionalanalyis%22 » funktionalanalysis%22, functionalanalytic%22, funktionsanalysis%22
funktionalanalyse%22 » funktionalanalysis%22, functionaalanalyse%22, funktionsanalyse%22

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: %_ (functionalanalysis%22 OR (funktionalanalyis%22 OR funktionalanalyse%22)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "%_ (functionalanalysis%22 or (funktionalanalyis%22 OR funktionalanalyse%22))".
• Adding a wildcard symbol may retrieve word variants: %_ (functionalanalysis%22 or (funktionalanalyis%22 OR funktionalanalyse%22))*.