Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petroiov (Expand Search), petriv (Expand Search)
petris » petri (Expand Search), peteris (Expand Search), petriis (Expand Search), petrois (Expand Search)
petru » pentru (Expand Search), petri (Expand Search), peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petruuio » pentruuio (Expand Search), petriuio (Expand Search), peteruuio (Expand Search), petriuuio (Expand Search), petrouuio (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (Expand Search)
petrio » peterio (Expand Search), petriio (Expand Search), petroio (Expand Search), petri (Expand Search), petro (Expand Search)
peteri » peterdi (Expand Search), peter (Expand Search), petri (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 (((petriov OR petris) OR petru) OR (((petr OR peteri) OR (petrio OR petruuio)) OR per)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petris) OR petru) OR (((petr OR peteri) OR (petrio OR petruuio)) OR per)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petris) OR petru) OR (((petr OR peteri) OR (petrio OR petruuio)) OR per)) o.s.*.