Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
peteriov » petrov (Expand Search)
petruoi » peteruoi (Expand Search), petriuoi (Expand Search), petruuoi (Expand Search)
petruuuo » peteruuuo (Expand Search), petriuuuo (Expand Search), petruuuuo (Expand Search)
petriuo » peteriuo (Expand Search), petriiuo (Expand Search), petruiuo (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 ((petriiov OR peteriov) OR (((petruoi OR petruoi) OR (petruuuo OR petriuo)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiov OR peteriov) OR (((petruoi OR petruoi) OR (petruuuo OR petriuo)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiov OR peteriov) OR (((petruoi OR petruoi) OR (petruuuo OR petriuo)) OR petr)) o.s.*.