Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petrv » petrov (Expand Search), petri (Expand Search), petru (Expand Search), petriv (Expand Search), petruv (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (Expand Search)
petriu » petriiu (Expand Search), petruiu (Expand Search), petroiu (Expand Search), petri (Expand Search), petru (Expand Search), petris (Expand Search)
petriiuv » petriiiuv (Expand Search), petruiiuv (Expand Search), petroiiuv (Expand Search)
peterv » peters (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 ((((petrv OR (petr OR petriu)) OR peterv) OR petriiuv) OR peteriv)) OR peter) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR ((((petrv OR (petr OR petriu)) OR peterv) OR petriiuv) OR peteriv)) OR peter) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR ((((petrv OR (petr OR petriu)) OR peterv) OR petriiuv) OR peteriv)) OR peter) o.s.*.