Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
petro » petrov (Expand Search), petri (Expand Search), petru (Expand Search), petero (Expand Search), petrio (Expand Search), petruo (Expand Search)
peterui » peterdi (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petriiio » peteriiio (Expand Search), petriiiio (Expand Search), petruiiio (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 petriiov) OR (((petro OR (petrui OR peterui)) OR petriiio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petriiov) OR (((petro OR (petrui OR peterui)) OR petriiio) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petriiov) OR (((petro OR (petrui OR peterui)) OR petriiio) OR petr)) o.s.*.