Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petroov » petrov (Expand Search), petrioov (Expand Search), petruoov (Expand Search), petrooov (Expand Search)
petroiv » petrov (Expand Search), petriv (Expand Search), petrovv (Expand Search), petrioiv (Expand Search), petruoiv (Expand Search), petrooiv (Expand Search)
petroi » petri (Expand Search), petro (Expand Search), petrov (Expand Search), petrioi (Expand Search), petruoi (Expand Search), petrooi (Expand Search)
petruoi » petriuoi (Expand Search), petruuoi (Expand Search), petrouoi (Expand Search)
petr » petri (Expand Search), petru (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 (((petruov OR petroov) OR petroiv) OR ((petroi OR petruoi) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruov OR petroov) OR petroiv) OR ((petroi OR petruoi) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruov OR petroov) OR petroiv) OR ((petroi OR petruoi) OR (petr OR peter))) o.s.*.