Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petruv » peteruv (Expand Search), petruuv (Expand Search), petrouv (Expand Search), petru (Expand Search), petrov (Expand Search)
petrouv » peterouv (Expand Search), petruouv (Expand Search), petroouv (Expand Search), petrov (Expand Search)
petruiv » peteruiv (Expand Search), petruuiv (Expand Search), petrouiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
peterov » petrov (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 petr) OR (((petruv OR petrouv) OR peterov) OR (petruiv OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR petr) OR (((petruv OR petrouv) OR peterov) OR (petruiv OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR petr) OR (((petruv OR petrouv) OR peterov) OR (petruiv OR petri))) o.s.*.