Perhaps you should try some spelling variations:
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (Expand Search)
petrov » peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petriuov » peteriuov (Expand Search), petriiuov (Expand Search), petruiuov (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (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 (((petriv OR petrov) OR (petruov OR petriuov)) OR ((petero OR (per OR petrui)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriv OR petrov) OR (petruov OR petriuov)) OR ((petero OR (per OR petrui)) OR petr)) o.s.*".