Perhaps you should try some spelling variations:
petrooiv » petrov (Expand Search), peterooiv (Expand Search), petriooiv (Expand Search), petruooiv (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petroov » peteroov (Expand Search), petrioov (Expand Search), petruoov (Expand Search)
petrooiov » peterooiov (Expand Search), petriooiov (Expand Search), petruooiov (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 ((petriv OR petrooiv) OR (((peteru OR petroi) OR (petroov OR petrooiov)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR petrooiv) OR (((peteru OR petroi) OR (petroov OR petrooiov)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriv OR petrooiv) OR (((peteru OR petroi) OR (petroov OR petrooiov)) OR petr)) o.s.*.