Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petruuov » petrov (Expand Search), peteruuov (Expand Search), petriuuov (Expand Search), petruuuov (Expand Search)
petriuo » peteriuo (Expand Search), petriiuo (Expand Search), petruiuo (Expand Search)
petriiuo » peteriiuo (Expand Search), petriiiuo (Expand Search), petruiiuo (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 petruuov) OR ((((petriuo OR petriiuo) OR petroi) OR petero) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((perov OR petruuov) OR ((((petriuo OR petriiuo) OR petroi) OR petero) OR petr)) o.s.*".