Perhaps you should try some spelling variations:
petruuov » petrov (Expand Search), peteruuov (Expand Search), petruuuov (Expand Search), petrouuov (Expand Search)
peteruov » petrov (Expand Search)
petroou » peteroou (Expand Search), petruoou (Expand Search), petrooou (Expand Search)
petrouou » peterouou (Expand Search), petruouou (Expand Search), petroouou (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (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 ((petruuov OR peteruov) OR (((petroou OR (petrouou OR peteruou)) OR petri) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruuov OR peteruov) OR (((petroou OR (petrouou OR peteruou)) OR petri) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruuov OR peteruov) OR (((petroou OR (petrouou OR peteruou)) OR petri) OR petr)) o.s.*.