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)
petriiiio » peteriiiio (Expand Search), petriiiiio (Expand Search), petruiiiio (Expand Search)
petriou » peteriou (Expand Search), petriiou (Expand Search), petruiou (Expand Search)
petruiou » peteruiou (Expand Search), petriuiou (Expand Search), petruuiou (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 (((peteruoio OR petriiiio) OR (petriou OR petruiou)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petruiv) OR (((peteruoio OR petriiiio) OR (petriou OR petruiou)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petruiv) OR (((peteruoio OR petriiiio) OR (petriou OR petruiou)) OR petr)) o.s.*.