Perhaps you should try some spelling variations:
petrov » petriv (Expand Search), petruv (Expand Search), peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petro » petri (Expand Search), petru (Expand Search), petero (Expand Search), petrio (Expand Search), petruo (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petruuio » peteruuio (Expand Search), petriuuio (Expand Search), petruuuio (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (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 ((petrov OR petruv) OR (((petro OR petruuio) OR petrui) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR petruv) OR (((petro OR petruuio) OR petrui) OR petr)) o.s.*".