Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), petruuov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petrv » petrov (Expand Search), petru (Expand Search), petro (Expand Search), petruv (Expand Search), perv (Expand Search)
petrui » petru (Expand Search), petruui (Expand Search), petroui (Expand Search), perui (Expand Search)
petriui » petruiui (Expand Search), petroiui (Expand Search), periui (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petrooi » petruooi (Expand Search), petroooi (Expand Search), perooi (Expand Search)
petr » petru (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 ((petruov OR (petrv OR (petrui OR petriui))) OR ((petri OR petrooi) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR (petrv OR (petrui OR petriui))) OR ((petri OR petrooi) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR (petrv OR (petrui OR petriui))) OR ((petri OR petrooi) OR (petr OR peter))) o.s.*.