Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruou » peteruou (Expand Search), petriuou (Expand Search), petruuou (Expand Search)
petruuou » peteruuou (Expand Search), petriuuou (Expand Search), petruuuou (Expand Search)
petriiu » peteriiu (Expand Search), petriiiu (Expand Search), petruiiu (Expand Search)
petruiu » peteruiu (Expand Search), petriuiu (Expand Search), petruuiu (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 (((petruou OR petruuou) OR ((petriiu OR petruiu) OR petriiu)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriov OR (((petruou OR petruuou) OR ((petriiu OR petruiu) OR petriiu)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petriov OR (((petruou OR petruuou) OR ((petriiu OR petruiu) OR petriiu)) OR petr)) o.s.*.