Perhaps you should try some spelling variations:
peteroov » petrov (Expand Search)
peru » per (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petroiv (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petrouov (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petrouo » peterouo (Expand Search), petriouo (Expand Search), petroouo (Expand Search)
petr » peter (Expand Search), petri (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 (((petriv OR petruov) OR petruov) OR (((peteroov OR (peru OR petru)) OR petrouo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriv OR petruov) OR petruov) OR (((peteroov OR (peru OR petru)) OR petrouo) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriv OR petruov) OR petruov) OR (((peteroov OR (peru OR petru)) OR petrouo) OR petr)) o.s.*.