Perhaps you should try some spelling variations:
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petrv » peterv (Expand Search), petruv (Expand Search), petrov (Expand Search)
petrov » peterov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petruuuv » peteruuuv (Expand Search), petruuuuv (Expand Search), petrouuuv (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (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 ((((petri OR peteri) OR peteri) OR petriov) OR (((petrv OR petrov) OR petruuuv) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petri OR peteri) OR peteri) OR petriov) OR (((petrv OR petrov) OR petruuuv) OR petr)) o.s.*".