Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petr » petri (Expand Search), petro (Expand Search), per (Expand Search)
petru » petriu (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search), petri (Expand Search)
petrou » petriou (Expand Search), petroou (Expand Search), perou (Expand Search), petro (Expand Search), petrov (Expand Search), petrow (Expand Search)
petriou » petriiou (Expand Search), petroiou (Expand Search), periou (Expand Search)
petrioou » petriioou (Expand Search), petroioou (Expand Search), perioou (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 ((petr OR (petru OR (((petrou OR petriou) OR periou) OR petrioou))) OR peter)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriov OR ((petr OR (petru OR (((petrou OR petriou) OR periou) OR petrioou))) OR peter)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petriov OR ((petr OR (petru OR (((petrou OR petriou) OR periou) OR petrioou))) OR peter)) o.s.*.