Perhaps you should try some spelling variations:
petrois » petris (Expand Search), petruois (Expand Search), petroois (Expand Search), perois (Expand Search)
petriov » petrov (Expand Search), petruiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petruiv » petruuiv (Expand Search), petrouiv (Expand Search), peruiv (Expand Search)
petruuiv » petruuuiv (Expand Search), petrouuiv (Expand Search), peruuiv (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (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 (((petruiv OR petrois) OR petruuiv) OR (((petriov OR petri) OR petr) OR peter)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruiv OR petrois) OR petruuiv) OR (((petriov OR petri) OR petr) OR peter)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruiv OR petrois) OR petruuiv) OR (((petriov OR petri) OR petr) OR peter)) o.s.*.