Perhaps you should try some spelling variations:
peterov » petrov (Expand Search)
petruov » petrov (Expand Search), peteruov (Expand Search), petrouov (Expand Search), pentruov (Expand Search)
petra » petro (Expand Search), petre (Expand Search), petera (Expand Search), petroa (Expand Search)
petruuv » peteruuv (Expand Search), petrouuv (Expand Search), pentruuv (Expand Search)
petr » peter (Expand Search), petro (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), pentru (Expand Search)
petri » peteri (Expand Search), petroi (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 ((((peterov OR petruov) OR petruuv) OR petra) OR (((petr OR per) OR petru) OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((peterov OR petruov) OR petruuv) OR petra) OR (((petr OR per) OR petru) OR petri)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((peterov OR petruov) OR petruuv) OR petra) OR (((petr OR per) OR petru) OR petri)) o.s.*.