Perhaps you should try some spelling variations:
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruiuiv » peteruiuiv (Expand Search), petriuiuiv (Expand Search), petruuiuiv (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (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 ((petriv OR (petriov OR petruiuiv)) OR (((petrui OR peteruo) OR petruov) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR (petriov OR petruiuiv)) OR (((petrui OR peteruo) OR petruov) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriv OR (petriov OR petruiuiv)) OR (((petrui OR peteruo) OR petruov) OR petr)) o.s.*.