Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petroiov (Expand Search)
petru » pentru (Expand Search), petri (Expand Search), peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petrou » petro (Expand Search), petrov (Expand Search), petrow (Expand Search), peterou (Expand Search), petriou (Expand Search), petroou (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (Expand Search)
peteri » peterdi (Expand Search), peter (Expand Search), petri (Expand Search)
peteru » peter (Expand Search), peters (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 petru) OR ((((petrou OR petr) OR peteri) OR (peteru OR peteru)) OR per)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petru) OR ((((petrou OR petr) OR peteri) OR (peteru OR peteru)) OR per)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petru) OR ((((petrou OR petr) OR peteri) OR (peteru OR peteru)) OR per)) o.s.*.