Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (Expand Search)
petriiiov » peteriiiov (Expand Search), petriiiiov (Expand Search), petruiiiov (Expand Search)
petriiio » peteriiio (Expand Search), petriiiio (Expand Search), petruiiio (Expand Search)
petriiiio » peteriiiio (Expand Search), petriiiiio (Expand Search), petruiiiio (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 petriov) OR petriv) OR petriiiov) OR ((petriiio OR petriiiio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriov OR petriov) OR petriv) OR petriiiov) OR ((petriiio OR petriiiio) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriov OR petriov) OR petriv) OR petriiiov) OR ((petriiio OR petriiiio) OR petr)) o.s.*.