Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), petruv (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petroiv » petrov (Expand Search), petrioiv (Expand Search), petruoiv (Expand Search), petrooiv (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), petriuo (Expand Search), petruuo (Expand Search), petrouo (Expand Search)
petriuiv » petriiuiv (Expand Search), petruiuiv (Expand Search), petroiuiv (Expand Search)
petriuo » petriiuo (Expand Search), petruiuo (Expand Search), petroiuo (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 (petroiv OR petriuiv)) OR ((petruo OR petriuo) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR (petroiv OR petriuiv)) OR ((petruo OR petriuo) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR (petroiv OR petriuiv)) OR ((petruo OR petriuo) OR (petr OR peter))) o.s.*.