Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petriiv » petriiiv (Expand Search), petruiiv (Expand Search), petroiiv (Expand Search)
petriuv » petriiuv (Expand Search), petruiuv (Expand Search), petroiuv (Expand Search)
petriio » petriiio (Expand Search), petruiio (Expand Search), petroiio (Expand Search)
petriuo » petriiuo (Expand Search), petruiuo (Expand Search), petroiuo (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (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 petriiv) OR petriuv) OR ((petriio OR petriuo) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petriiv) OR petriuv) OR ((petriio OR petriuo) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petriiv) OR petriuv) OR ((petriio OR petriuo) OR (petr OR peter))) o.s.*.