Perhaps you should try some spelling variations:
petriiiv » petriiiiv (Expand Search), petroiiiv (Expand Search), periiiv (Expand Search)
petruiv » petriuiv (Expand Search), petrouiv (Expand Search), peruiv (Expand Search), pentruiv (Expand Search), petriiv (Expand Search)
petr » petri (Expand Search), petro (Expand Search), per (Expand Search)
petru » petriu (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search), petri (Expand Search)
petroi » petrioi (Expand Search), petrooi (Expand Search), peroi (Expand Search), petri (Expand Search), petro (Expand Search), petrov (Expand Search)
petrois » petriois (Expand Search), petroois (Expand Search), perois (Expand Search), petris (Expand Search), petros (Expand Search), petrovs (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 ((petriiiv OR petruiv) OR ((((petr OR petru) OR petroi) OR (petrois OR perio)) OR peter)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiiv OR petruiv) OR ((((petr OR petru) OR petroi) OR (petrois OR perio)) OR peter)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiiv OR petruiv) OR ((((petr OR petru) OR petroi) OR (petrois OR perio)) OR peter)) o.s.*.