Perhaps you should try some spelling variations:
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petruuv » peteruuv (Expand Search), petriuuv (Expand Search), petruuuv (Expand Search)
petriiouv » peteriiouv (Expand Search), petriiiouv (Expand Search), petruiiouv (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petrouo » peterouo (Expand Search), petriouo (Expand Search), petruouo (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 (petruuv OR petriiouv)) OR ((petrui OR (peteruo OR petrouo)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR (petruuv OR petriiouv)) OR ((petrui OR (peteruo OR petrouo)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR (petruuv OR petriiouv)) OR ((petrui OR (peteruo OR petrouo)) OR petr)) o.s.*.