Perhaps you should try some spelling variations:
petrv » petrov (Expand Search), petri (Expand Search), petru (Expand Search), peterv (Expand Search), petriv (Expand Search), petruv (Expand Search)
petruov » petrov (Expand Search), peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruuv » peteruuv (Expand Search), petriuuv (Expand Search), petruuuv (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (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 ((petrv OR (petruuv OR (petruov OR petriov))) OR (petr OR (petrui OR peterdi))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrv OR (petruuv OR (petruov OR petriov))) OR (petr OR (petrui OR peterdi))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petrv OR (petruuv OR (petruov OR petriov))) OR (petr OR (petrui OR peterdi))) o.s.*.