Perhaps you should try some spelling variations:
petriiv » peteriiv (Expand Search), petroiiv (Expand Search), periiv (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petrov » peterov (Expand Search), petroov (Expand Search), perov (Expand Search)
petriov » peteriov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petr » peter (Expand Search), petro (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 (petriiv OR ((((petri OR petru) OR (petrov OR petriov)) OR (peterio OR perio)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriiv OR ((((petri OR petru) OR (petrov OR petriov)) OR (peterio OR perio)) OR petr)) o.s.*".