Perhaps you should try some spelling variations:
peterov » petrov (Expand Search)
petroov » petrov (Expand Search), peteroov (Expand Search), petruoov (Expand Search), petrooov (Expand Search)
peterv » peter (Expand Search), peters (Expand Search)
petruo » petru (Expand Search), petro (Expand Search), peteruo (Expand Search), petruuo (Expand Search), petrouo (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petroi » peteroi (Expand Search), petruoi (Expand Search), petrooi (Expand Search), petro (Expand Search), petrov (Expand Search), petrow (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 ((((peterov OR petroov) OR peterov) OR peterv) OR (petruo OR (petr OR (petroi OR petri)))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((peterov OR petroov) OR peterov) OR peterv) OR (petruo OR (petr OR (petroi OR petri)))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((peterov OR petroov) OR peterov) OR peterv) OR (petruo OR (petr OR (petroi OR petri)))) o.s.*.