Perhaps you should try some spelling variations:
petruuov » petrov (Expand Search), peteruuov (Expand Search), petriuuov (Expand Search), petruuuov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petriio » peteriio (Expand Search), petriiio (Expand Search), petruiio (Expand Search)
petriuio » peteriuio (Expand Search), petriiuio (Expand Search), petruiuio (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (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 ((petruuov OR petriov) OR (((petriio OR petriuio) OR (peteruv OR petriv)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruuov OR petriov) OR (((petriio OR petriuio) OR (peteruv OR petriv)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruuov OR petriov) OR (((petriio OR petriuio) OR (peteruv OR petriv)) OR petr)) o.s.*.