Perhaps you should try some spelling variations:
petruv » petrov (Expand Search), pentruv (Expand Search), petriv (Expand Search)
petriv » petri (Expand Search), petris (Expand Search), petrov (Expand Search)
petruiv » pentruiv (Expand Search), petriiv (Expand Search)
petru » pentru (Expand Search), petri (Expand Search)
petruo » pentruo (Expand Search), petrio (Expand Search), petro (Expand Search)
pero » petro (Expand Search), per (Expand Search), pro (Expand Search)
peters » petersen (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 (((petruv OR petriv) OR petruiv) OR ((((petru OR pero) OR peters) OR petruo) OR peter)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruv OR petriv) OR petruiv) OR ((((petru OR pero) OR peters) OR petruo) OR peter)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruv OR petriv) OR petruiv) OR ((((petru OR pero) OR peters) OR petruo) OR peter)) o.s.*.