Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), peteriov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search)
petroou » peteroou (Expand Search), petrooou (Expand Search), peroou (Expand Search)
petruov » peteruov (Expand Search), petrouov (Expand Search), peruov (Expand Search), pentruov (Expand Search), petrov (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)
petero » peter (Expand Search), peters (Expand Search), petro (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 periv) OR ((((petr OR (petru OR petroou)) OR petero) OR petruov) OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR periv) OR ((((petr OR (petru OR petroou)) OR petero) OR petruov) OR petri)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR periv) OR ((((petr OR (petru OR petroou)) OR petero) OR petruov) OR petri)) o.s.*.