Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petruv » petru (Expand Search), petrov (Expand Search), peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petruiiv (Expand Search)
petruou » peteruou (Expand Search), petriuou (Expand Search), petruuou (Expand Search)
petriou » peteriou (Expand Search), petriiou (Expand Search), petruiou (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 (((petruov OR petruv) OR (petriiv OR (petruou OR petriou))) OR (petr OR per)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruov OR petruv) OR (petriiv OR (petruou OR petriou))) OR (petr OR per)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruov OR petruv) OR (petriiv OR (petruou OR petriou))) OR (petr OR per)) o.s.*.