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