Perhaps you should try some spelling variations:
petro » petrov (Expand Search), petri (Expand Search), petero (Expand Search), petrio (Expand Search), pero (Expand Search)
peri » petri (Expand Search), per (Expand Search)
perio » petrio (Expand Search), pero (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), peruv (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), peruov (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), peru (Expand Search)
petr » peter (Expand Search), petri (Expand Search), per (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 ((petruv OR petruov) OR ((((petro OR peri) OR petru) OR perio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR petruov) OR ((((petro OR peri) OR petru) OR perio) OR petr)) o.s.*".