Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), peteruov (Expand Search), petrouov (Expand Search), peruov (Expand Search), pentruov (Expand Search)
petruuo » peteruuo (Expand Search), petrouuo (Expand Search), peruuo (Expand Search), pentruuo (Expand Search)
petruiuo » peteruiuo (Expand Search), petrouiuo (Expand Search), peruiuo (Expand Search), pentruiuo (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (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 petruov) OR (((petruuo OR petruiuo) OR petr) OR (petru OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR petruov) OR (((petruuo OR petruiuo) OR petr) OR (petru OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR petruov) OR (((petruuo OR petruiuo) OR petr) OR (petru OR petri))) o.s.*.