Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
peri » per (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)
petroi » peteroi (Expand Search), petrooi (Expand Search), peroi (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petruo » peteruo (Expand Search), petrouo (Expand Search), peruo (Expand Search)
petrouo » peterouo (Expand Search), petroouo (Expand Search), perouo (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 (((((peri OR petri) OR petroi) OR petru) OR (petruo OR petrouo)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (perov OR (((((peri OR petri) OR petroi) OR petru) OR (petruo OR petrouo)) OR petr)) o.s.*".