Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruuiov » peteruuiov (Expand Search), petriuuiov (Expand Search), petruuuiov (Expand Search)
petriuuov » peteriuuov (Expand Search), petriiuuov (Expand Search), petruiuuov (Expand Search)
petriiu » peteriiu (Expand Search), petriiiu (Expand Search), petruiiu (Expand Search)
petriuo » peteriuo (Expand Search), petriiuo (Expand Search), petruiuo (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 petruuiov) OR ((((peterov OR petriuuov) OR petriiu) OR petriuo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petruuiov) OR ((((peterov OR petriuuov) OR petriiu) OR petriuo) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petruuiov) OR ((((peterov OR petriuuov) OR petriiu) OR petriuo) OR petr)) o.s.*.