Perhaps you should try some spelling variations:
petruv » petrov (Expand Search), pentruv (Expand Search), petriv (Expand Search), petriuv (Expand Search), petrouv (Expand Search), peruv (Expand Search)
petris » petri (Expand Search), petriis (Expand Search), petrois (Expand Search), peris (Expand Search)
peters » petersen (Expand Search)
petru » pentru (Expand Search), petri (Expand Search), petriu (Expand Search), petrou (Expand Search), peru (Expand Search)
petroi » petri (Expand Search), petro (Expand Search), petrov (Expand Search), petrioi (Expand Search), petrooi (Expand Search), peroi (Expand Search)
petr » petri (Expand Search), 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 petris) OR ((((peters OR petru) OR peruo) OR petroi) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR petris) OR ((((peters OR petru) OR peruo) OR petroi) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruv OR petris) OR ((((peters OR petru) OR peruo) OR petroi) OR (petr OR peter))) o.s.*.