Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petruov » peteruov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petriu » peteriu (Expand Search), petroiu (Expand Search), periu (Expand Search)
petrooiu » peterooiu (Expand Search), petroooiu (Expand Search), perooiu (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)

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 (((petri OR petru) OR (petriu OR petrooiu)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((perov OR petruov) OR (((petri OR petru) OR (petriu OR petrooiu)) OR petr)) o.s.*".