Perhaps you should try some spelling variations:
petrov » petro (Expand Search), peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petruv » petru (Expand Search), peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petrui » petri (Expand Search), petru (Expand Search), peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), peteruo (Expand Search), petriuo (Expand Search), petruuo (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search), petri (Expand Search), petro (Expand Search), petrow (Expand Search)
peteru » peter (Expand Search), petru (Expand Search), peters (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 ((petrui OR petruo) OR ((petr OR peteru) OR (petroi OR petrui)))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR petruv) OR ((petrui OR petruo) OR ((petr OR peteru) OR (petroi OR petrui)))) o.s.*".