Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petruiiv (Expand Search)
petrv » peterv (Expand Search), petriv (Expand Search), petruv (Expand Search)
petrio » peterio (Expand Search), petriio (Expand Search), petruio (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petruiu (Expand Search)
petriiio » peteriiio (Expand Search), petriiiio (Expand Search), petruiiio (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 ((((petriiv OR perov) OR periiuv) OR petrv) OR (((petrio OR petriu) OR petriiio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriiv OR perov) OR periiuv) OR petrv) OR (((petrio OR petriu) OR petriiio) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriiv OR perov) OR periiuv) OR petrv) OR (((petrio OR petriu) OR petriiio) OR petr)) o.s.*.