Perhaps you should try some spelling variations:
petruov » pentruov (Expand Search), petrov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petru » pentru (Expand Search), petrou (Expand Search), peru (Expand Search)
petruo » pentruo (Expand Search), petro (Expand Search), petrouo (Expand Search), peruo (Expand Search)
petero » peters (Expand Search), petro (Expand Search)
petri » petroi (Expand Search), peri (Expand Search)
petr » petro (Expand Search), per (Expand Search)
petrov » petroov (Expand Search), perov (Expand Search), petro (Expand Search)

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 (((petero OR petri) OR petruo) OR ((petr OR petrov) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR petru) OR (((petero OR petri) OR petruo) OR ((petr OR petrov) OR peter))) o.s.*".