Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petero » peter (Expand Search), petro (Expand Search)
pero » petro (Expand Search), per (Expand Search), pro (Expand Search)
peters » peter (Expand Search), petersen (Expand Search)
petruuo » peteruuo (Expand Search), petruuuo (Expand Search), petrouuo (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (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 (petruov OR (((((petero OR petruuo) OR pero) OR petruuo) OR peters) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petruov OR (((((petero OR petruuo) OR pero) OR petruuo) OR peters) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petruov OR (((((petero OR petruuo) OR pero) OR petruuo) OR peters) OR (petr OR petri))) o.s.*.