Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), peteruov (Expand Search), petrouov (Expand Search), peruov (Expand Search), pentruov (Expand Search)
petruv » petrov (Expand Search), peteruv (Expand Search), petrouv (Expand Search), peruv (Expand Search), pentruv (Expand Search)
peters » peter (Expand Search), petersen (Expand Search)
peteru » peter (Expand Search)
petriio » peteriio (Expand Search), petroiio (Expand Search), periio (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)
petri » peteri (Expand Search), petroi (Expand Search), peri (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 ((petruov OR petruv) OR (((peters OR petriio) OR peteru) OR ((petr OR petru) OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR petruv) OR (((peters OR petriio) OR peteru) OR ((petr OR petru) OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR petruv) OR (((peters OR petriio) OR peteru) OR ((petr OR petru) OR petri))) o.s.*.