Perhaps you should try some spelling variations:
peri » petri (Expand Search), per (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petrouov (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petruo » peteruo (Expand Search), petriuo (Expand Search), petrouo (Expand Search)
petrouo » peterouo (Expand Search), petriouo (Expand Search), petroouo (Expand Search)
petruuo » peteruuo (Expand Search), petriuuo (Expand Search), petrouuo (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 ((petruov OR peterv) OR (((petru OR peri) OR ((petruo OR petrouo) OR petruuo)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR peterv) OR (((petru OR peri) OR ((petruo OR petrouo) OR petruuo)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR peterv) OR (((petru OR peri) OR ((petruo OR petrouo) OR petruuo)) OR petr)) o.s.*.