Perhaps you should try some spelling variations:
petruuv » peteruuv (Expand Search), petruuuv (Expand Search), petrouuv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrov » peterov (Expand Search), petruov (Expand Search), petroov (Expand Search)
petriui » peteriui (Expand Search), petruiui (Expand Search), petroiui (Expand Search)
petrio » peterio (Expand Search), petruio (Expand Search), petroio (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 peruov) OR (((((petri OR petrov) OR petriui) OR peteru) OR petrio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruuv OR peruov) OR (((((petri OR petrov) OR petriui) OR peteru) OR petrio) OR petr)) o.s.*".