Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
peterov » petrov (Expand Search)
petr » petri (Expand Search), petro (Expand Search), per (Expand Search)
petrui » petriui (Expand Search), petroui (Expand Search), perui (Expand Search), petri (Expand Search), pentrui (Expand Search), petrii (Expand Search)
petru » petriu (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search), petri (Expand Search)
petriui » petriiui (Expand Search), petroiui (Expand Search), periui (Expand Search)
peters » petersen (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: fop (((petriov OR peterov) OR (petr OR peter)) OR (((petrui OR petru) OR petriui) OR peters)) _. s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR peterov) OR (petr OR peter)) OR (((petrui OR petru) OR petriui) OR peters)) _. s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR peterov) OR (petr OR peter)) OR (((petrui OR petru) OR petriui) OR peters)) _. s.*.