Perhaps you should try some spelling variations:
petriv » petrov (Expand Search), peteriv (Expand Search), petroiv (Expand Search), periv (Expand Search)
petruo » petro (Expand Search), pentruo (Expand Search), peteruo (Expand Search), petrouo (Expand Search), peruo (Expand Search)
petruiv » pentruiv (Expand Search), peteruiv (Expand Search), petrouiv (Expand Search), peruiv (Expand Search)
petru » pentru (Expand Search), peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petris » peteris (Expand Search), petrois (Expand Search), peris (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (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 ((((petriv OR petris) OR petruiv) OR peroiv) OR ((petruo OR petru) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriv OR petris) OR petruiv) OR peroiv) OR ((petruo OR petru) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriv OR petris) OR petruiv) OR peroiv) OR ((petruo OR petru) OR (petr OR petri))) o.s.*.