Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
peru » petru (Expand Search), per (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petrou » peterou (Expand Search), petriou (Expand Search), petruou (Expand Search)
petrooiu » peterooiu (Expand Search), petriooiu (Expand Search), petruooiu (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 (perov OR (((petruov OR petriov) OR (((petrou OR peteru) OR petrooiu) OR peru)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (perov OR (((petruov OR petriov) OR (((petrou OR peteru) OR petrooiu) OR peru)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (perov OR (((petruov OR petriov) OR (((petrou OR peteru) OR petrooiu) OR peru)) OR petr)) o.s.*.