Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petroov » peteroov (Expand Search), petrioov (Expand Search), petruoov (Expand Search)
petrou » peterou (Expand Search), petriou (Expand Search), petruou (Expand Search)
petruou » peteruou (Expand Search), petriuou (Expand Search), petruuou (Expand Search)
petriiou » peteriiou (Expand Search), petriiiou (Expand Search), petruiiou (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 petroov) OR (((petrou OR (petruou OR peteruou)) OR petriiou) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petroov) OR (((petrou OR (petruou OR peteruou)) OR petriiou) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petroov) OR (((petrou OR (petruou OR peteruou)) OR petriiou) OR petr)) o.s.*.