Perhaps you should try some spelling variations:
petriuov » petrov (Expand Search), peteriuov (Expand Search), petriiuov (Expand Search), petruiuov (Expand Search)
petrouov » petrov (Expand Search), peterouov (Expand Search), petriouov (Expand Search), petruouov (Expand Search)
petruo » peteruo (Expand Search), petriuo (Expand Search), petruuo (Expand Search)
petruuo » peteruuo (Expand Search), petriuuo (Expand Search), petruuuo (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petruiui » peteruiui (Expand Search), petriuiui (Expand Search), petruuiui (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petriuov OR petrouov) OR (((petruo OR petruuo) OR (petroi OR petruiui)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriuov OR petrouov) OR (((petruo OR petruuo) OR (petroi OR petruiui)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriuov OR petrouov) OR (((petruo OR petruuo) OR (petroi OR petruiui)) OR petr)) o.s.*.