Perhaps you should try some spelling variations:
petriv » petri (Expand Search), petris (Expand Search), petrov (Expand Search), petriiv (Expand Search), petruiv (Expand Search), petroiv (Expand Search)
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petruv » petru (Expand Search), petrov (Expand Search), petriuv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
petrouv » petrov (Expand Search), petriouv (Expand Search), petruouv (Expand Search), petroouv (Expand Search)
petruiiv » petriuiiv (Expand Search), petruuiiv (Expand Search), petrouiiv (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 ((petriv OR petruiiv) OR ((petriov OR (petruv OR petrouv)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR petruiiv) OR ((petriov OR (petruv OR petrouv)) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriv OR petruiiv) OR ((petriov OR (petruv OR petrouv)) OR (petr OR peter))) o.s.*.