Perhaps you should try some spelling variations:
petrovov » petrov (Expand Search), peterovov (Expand Search), petriovov (Expand Search), petruovov (Expand Search)
petruvov » petrov (Expand Search), peteruvov (Expand Search), petriuvov (Expand Search), petruuvov (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petrio » peterio (Expand Search), petriio (Expand Search), petruio (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 ((petruov OR (petrovov OR petruvov)) OR (petrui OR (petrio OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR (petrovov OR petruvov)) OR (petrui OR (petrio OR petr))) o.s.*".