Perhaps you should try some spelling variations:
petruoov » petrov (Expand Search), peteruoov (Expand Search), petriuoov (Expand Search), petruuoov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petrioi » peterioi (Expand Search), petriioi (Expand Search), petruioi (Expand Search)
petruiiuo » peteruiiuo (Expand Search), petriuiiuo (Expand Search), petruuiiuo (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 petruov) OR petruoov) OR (((petroi OR petrioi) OR petruiiuo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petruov) OR petruoov) OR (((petroi OR petrioi) OR petruiiuo) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petruov) OR petruoov) OR (((petroi OR petrioi) OR petruiiuo) OR petr)) o.s.*.