Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petruiiov (Expand Search), petroiiov (Expand Search)
petriiiv » peteriiiv (Expand Search), petruiiiv (Expand Search), petroiiiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrio » peterio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petruov » peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petruv » peteruv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petriiiv OR petriiov) OR (((petri OR petrio) OR (petruov OR petruv)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiiv OR petriiov) OR (((petri OR petrio) OR (petruov OR petruv)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiiv OR petriiov) OR (((petri OR petrio) OR (petruov OR petruv)) OR petr)) o.s.*.