Perhaps you should try some spelling variations:
petroov » petrov (Expand Search), peteroov (Expand Search), petrioov (Expand Search), petrooov (Expand Search)
petriv » petri (Expand Search), petris (Expand Search), petrov (Expand Search), peteriv (Expand Search), petriiv (Expand Search), petroiv (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (Expand Search)
petruo » peteruo (Expand Search), petriuo (Expand Search), petrouo (Expand Search), petro (Expand Search), pentruo (Expand Search), petrio (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search), pentru (Expand Search), petri (Expand Search)
petrooi » peterooi (Expand Search), petriooi (Expand Search), petroooi (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 ((petroov OR petriv) OR (((petr OR (petruo OR petru)) OR (petrooi OR petrooi)) OR per)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroov OR petriv) OR (((petr OR (petruo OR petru)) OR (petrooi OR petrooi)) OR per)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petroov OR petriv) OR (((petr OR (petruo OR petru)) OR (petrooi OR petrooi)) OR per)) o.s.*.