Perhaps you should try some spelling variations:
petrooiv » petrov (Expand Search), peterooiv (Expand Search), petruooiv (Expand Search), petroooiv (Expand Search)
peteroov » petrov (Expand Search)
petroiv » peteroiv (Expand Search), petruoiv (Expand Search), petrooiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrooiov » peterooiov (Expand Search), petruooiov (Expand Search), petroooiov (Expand Search)
petr » peter (Expand Search), petru (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 ((petroiv OR petrooiv) OR (((peteru OR petri) OR (peteroov OR petrooiov)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroiv OR petrooiv) OR (((peteru OR petri) OR (peteroov OR petrooiov)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petroiv OR petrooiv) OR (((peteru OR petri) OR (peteroov OR petrooiov)) OR petr)) o.s.*.