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