Perhaps you should try some spelling variations:
petrouiv » petrov (Expand Search), peterouiv (Expand Search), petriouiv (Expand Search), petroouiv (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petroiiv (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petriio » peteriio (Expand Search), petriiio (Expand Search), petroiio (Expand Search)
petroiio » peteroiio (Expand Search), petrioiio (Expand Search), petrooiio (Expand Search)
petr » peter (Expand Search), petri (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 ((petriiv OR petrouiv) OR (((petru OR petriiv) OR (petriio OR petroiio)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiv OR petrouiv) OR (((petru OR petriiv) OR (petriio OR petroiio)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiv OR petrouiv) OR (((petru OR petriiv) OR (petriio OR petroiio)) OR petr)) o.s.*.