Perhaps you should try some spelling variations:
petruuov » petrov (Expand Search), peteruuov (Expand Search), petruuuov (Expand Search), petrouuov (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petriv » peteriv (Expand Search), petruiv (Expand Search), petroiv (Expand Search)
petriiv » peteriiv (Expand Search), petruiiv (Expand Search), petroiiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petr » peter (Expand Search), petru (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 ((((petriov OR (petriv OR petriiv)) OR petruuov) OR peterv) OR ((petri OR per) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriov OR (petriv OR petriiv)) OR petruuov) OR peterv) OR ((petri OR per) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriov OR (petriv OR petriiv)) OR petruuov) OR peterv) OR ((petri OR per) OR petr)) o.s.*.