Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruiv » peteruiv (Expand Search), petriuiv (Expand Search), petruuiv (Expand Search)
petruoio » peteruoio (Expand Search), petriuoio (Expand Search), petruuoio (Expand Search)
petriiuoio » peteriiuoio (Expand Search), petriiiuoio (Expand Search), petruiiuoio (Expand Search)
petriio » peteriio (Expand Search), petriiio (Expand Search), petruiio (Expand Search)
petrou » peterou (Expand Search), petriou (Expand Search), petruou (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 petruiv) OR ((((petruoio OR petriiuoio) OR petriio) OR petrou) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petruiv) OR ((((petruoio OR petriiuoio) OR petriio) OR petrou) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petruiv) OR ((((petruoio OR petriiuoio) OR petriio) OR petrou) OR petr)) o.s.*.