Perhaps you should try some spelling variations:
petrov » petriv (Expand Search), petruv (Expand Search), peterov (Expand Search), petriov (Expand Search), petruov (Expand Search)
petro » petri (Expand Search), petru (Expand Search), petero (Expand Search), petrio (Expand Search), petruo (Expand Search)
peruv » petruv (Expand Search), perv (Expand Search)
peru » petru (Expand Search), per (Expand Search)
petriio » peteriio (Expand Search), petriiio (Expand Search), petruiio (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 ((peruv OR petrov) OR ((((petro OR perov) OR peru) OR (petriio OR peterio)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((peruv OR petrov) OR ((((petro OR perov) OR peru) OR (petriio OR peterio)) OR petr)) o.s.*".