Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
petruuv » peteruuv (Expand Search), petriuuv (Expand Search), petruuuv (Expand Search)
petruo » peteruo (Expand Search), petriuo (Expand Search), petruuo (Expand Search)
petriuo » peteriuo (Expand Search), petriiuo (Expand Search), petruiuo (Expand Search)
petriiuo » peteriiuo (Expand Search), petriiiuo (Expand Search), petruiiuo (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 petruuv) OR (((petruo OR peteriu) OR (petriuo OR petriiuo)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiov OR petruuv) OR (((petruo OR peteriu) OR (petriuo OR petriiuo)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiov OR petruuv) OR (((petruo OR peteriu) OR (petriuo OR petriiuo)) OR petr)) o.s.*.