Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petroiiov (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petroiiv (Expand Search)
petroiv » peteroiv (Expand Search), petrioiv (Expand Search), petrooiv (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petrooi (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petroiov (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 petroiv) OR (((petru OR petroi) OR (petriov OR petriiov)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiv OR petroiv) OR (((petru OR petroi) OR (petriov OR petriiov)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiv OR petroiv) OR (((petru OR petroi) OR (petriov OR petriiov)) OR petr)) o.s.*.