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)
petr » petri (Expand Search), petru (Expand Search), petro (Expand Search)
petruov » petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search), petrov (Expand Search)
petroov » petrioov (Expand Search), petruoov (Expand Search), petrooov (Expand Search), petrov (Expand Search)
petruv » petriuv (Expand Search), petruuv (Expand Search), petrouv (Expand Search), petru (Expand Search), petrov (Expand Search)
petriuv » petriiuv (Expand Search), petruiuv (Expand Search), petroiuv (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 peter) OR (petr OR (((petruov OR petroov) OR (petruv OR petriuv)) OR petriv))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR peter) OR (petr OR (((petruov OR petroov) OR (petruv OR petriuv)) OR petriv))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriv OR peter) OR (petr OR (((petruov OR petroov) OR (petruv OR petriuv)) OR petriv))) o.s.*.