Perhaps you should try some spelling variations:
petrov » peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petrouov » peterouov (Expand Search), petriouov (Expand Search), petruouov (Expand Search)
petriouov » peteriouov (Expand Search), petriiouov (Expand Search), petruiouov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petroouo » peteroouo (Expand Search), petrioouo (Expand Search), petruoouo (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 (petrouov OR petriouov)) OR ((petroi OR (peteruouo OR petroouo)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR (petrouov OR petriouov)) OR ((petroi OR (peteruouo OR petroouo)) OR petr)) o.s.*".