Perhaps you should try some spelling variations:
petrv » petrov (Expand Search), petri (Expand Search), petru (Expand Search), petriv (Expand Search), petruv (Expand Search)
peterov » petrov (Expand Search)
petruuv » petriuuv (Expand Search), petruuuv (Expand Search), petrouuv (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (Expand Search)
petrui » petriui (Expand Search), petruui (Expand Search), petroui (Expand Search), petri (Expand Search), petru (Expand Search)
peteri » petri (Expand Search), 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 ((petrv OR (petruuv OR peterov)) OR ((petr OR peter) OR ((petrui OR peteri) OR peterdi))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrv OR (petruuv OR peterov)) OR ((petr OR peter) OR ((petrui OR peteri) OR peterdi))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petrv OR (petruuv OR peterov)) OR ((petr OR peter) OR ((petrui OR peteri) OR peterdi))) o.s.*.