Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petrisv (Expand Search), peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
peterov » petrov (Expand Search)
petrv » petrov (Expand Search), petru (Expand Search), petro (Expand Search), peterv (Expand Search), petruv (Expand Search)
petrio » petris (Expand Search), petro (Expand Search), peterio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 peterov) OR petriov) OR peterov) OR petrv) OR (petrio OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((((petriov OR peterov) OR petriov) OR peterov) OR petrv) OR (petrio OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((((petriov OR peterov) OR petriov) OR peterov) OR petrv) OR (petrio OR (petr OR petri))) o.s.*.