Perhaps you should try some spelling variations:
petriiv » peteriiv (Expand Search), petruiiv (Expand Search), petroiiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrui » peterui (Expand Search), petruui (Expand Search), petroui (Expand Search)
petroui » peteroui (Expand Search), petruoui (Expand Search), petrooui (Expand Search)
petrio » peterio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petr » peter (Expand Search), petru (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 (petriiv OR ((((petero OR petero) OR (petri OR (petrui OR petroui))) OR petrio) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriiv OR ((((petero OR petero) OR (petri OR (petrui OR petroui))) OR petrio) OR petr)) o.s.*".