Perhaps you should try some spelling variations:
petruuv » peteruuv (Expand Search), petruuuv (Expand Search), petrouuv (Expand Search)
petrov » peterov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petruuo » peteruuo (Expand Search), petruuuo (Expand Search), petrouuo (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrui » peterui (Expand Search), petruui (Expand Search), petroui (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (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 ((petruuv OR petrov) OR ((((pero OR petruuo) OR (petri OR petrui)) OR petruuo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruuv OR petrov) OR ((((pero OR petruuo) OR (petri OR petrui)) OR petruuo) OR petr)) o.s.*".