Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruio » peteruio (Expand Search), petriuio (Expand Search), petruuio (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)
petrioi » peterioi (Expand Search), petriioi (Expand Search), petruioi (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petruiu (Expand Search), petri (Expand Search), petru (Expand Search), petris (Expand Search)
petriiu » peteriiu (Expand Search), petriiiu (Expand Search), petruiiu (Expand Search)
petroiu » peteroiu (Expand Search), petrioiu (Expand Search), petruoiu (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 petruio) o) OR (((petr OR petrioi) OR ((petriu OR petriiu) OR petroiu)) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petruio) o) OR (((petr OR petrioi) OR ((petriu OR petriiu) OR petroiu)) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petruio) o) OR (((petr OR petrioi) OR ((petriu OR petriiu) OR petroiu)) _)). s.*.