Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), pentruov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petru » pentru (Expand Search), petrou (Expand Search), peru (Expand Search)
petruv » pentruv (Expand Search), petrov (Expand Search), petrouv (Expand Search), peruv (Expand Search)
petra » petro (Expand Search), petre (Expand Search), petroa (Expand Search), pera (Expand Search)
petriv » petris (Expand Search), petrov (Expand Search), petroiv (Expand Search), periv (Expand Search)
petri » petroi (Expand Search), peri (Expand Search)
petr » petro (Expand Search), per (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 petru) OR ((((petra OR petri) OR petruv) OR petriv) OR petr)) OR peter) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruov OR petru) OR ((((petra OR petri) OR petruv) OR petriv) OR petr)) OR peter) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruov OR petru) OR ((((petra OR petri) OR petruv) OR petriv) OR petr)) OR peter) o.s.*.