Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petruuov » petrov (Expand Search), peteruuov (Expand Search), petriuuov (Expand Search), petruuuov (Expand Search)
petrouuuov » peterouuuov (Expand Search), petriouuuov (Expand Search), petruouuuov (Expand Search)
petruo » peteruo (Expand Search), petriuo (Expand Search), petruuo (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 peterov) OR (petruuov OR petrouuuov)) OR ((petruo OR petroi) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((perov OR peterov) OR (petruuov OR petrouuuov)) OR ((petruo OR petroi) OR petr)) o.s.*".