Perhaps you should try some spelling variations:
petruv » petrov (Expand Search), pentruv (Expand Search), petrouv (Expand Search), peruv (Expand Search)
petru » pentru (Expand Search), petrou (Expand Search), peru (Expand Search)
petruuo » pentruuo (Expand Search), petrouuo (Expand Search), peruuo (Expand Search)
petero » peters (Expand Search), petro (Expand Search)
petriuv » petroiuv (Expand Search), periuv (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 ((petruv OR petriuv) OR ((((petru OR petri) OR petero) OR petruuo) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR petriuv) OR ((((petru OR petri) OR petero) OR petruuo) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruv OR petriuv) OR ((((petru OR petri) OR petero) OR petruuo) OR (petr OR peter))) o.s.*.