Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petruiov » petrov (Expand Search), peteruiov (Expand Search), petriuiov (Expand Search), petruuiov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruuo » peteruuo (Expand Search), petriuuo (Expand Search), petruuuo (Expand Search)
petrouoov » peterouoov (Expand Search), petriouoov (Expand Search), petruouoov (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 (petriov OR petruiov)) OR (((petruuo OR petrouoov) OR peteri) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((perov OR (petriov OR petruiov)) OR (((petruuo OR petrouoov) OR peteri) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((perov OR (petriov OR petruiov)) OR (((petruuo OR petrouoov) OR peteri) OR petr)) o.s.*.