Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruiiov » peteruiiov (Expand Search), petriuiiov (Expand Search), petruuiiov (Expand Search)
petrioiov » peterioiov (Expand Search), petriioiov (Expand Search), petruioiov (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petroov » peteroov (Expand Search), petrioov (Expand Search), petruoov (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 petruiiov) OR petrioiov) OR ((petrui OR (peterov OR petroov)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petruiiov) OR petrioiov) OR ((petrui OR (peterov OR petroov)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petruiiov) OR petrioiov) OR ((petrui OR (peterov OR petroov)) OR petr)) o.s.*.