Perhaps you should try some spelling variations:
petrooov » petrov (Expand Search), peterooov (Expand Search), petriooov (Expand Search), petruooov (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petruoui » peteruoui (Expand Search), petriuoui (Expand Search), petruuoui (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 petrooov) OR peteriv) OR (((petrui OR petroi) OR petruoui) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruov OR petrooov) OR peteriv) OR (((petrui OR petroi) OR petruoui) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruov OR petrooov) OR peteriv) OR (((petrui OR petroi) OR petruoui) OR petr)) o.s.*.