Perhaps you should try some spelling variations:
petrov » peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petrioov » peterioov (Expand Search), petriioov (Expand Search), petruioov (Expand Search)
petriiov » peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
petruiuou » peteruiuou (Expand Search), petriuiuou (Expand Search), petruuiuou (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petruiu (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 (petrioov OR petriiov)) OR (((peterou OR petruiuou) OR petriu) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR (petrioov OR petriiov)) OR (((peterou OR petruiuou) OR petriu) OR petr)) o.s.*".