Perhaps you should try some spelling variations:
peri » per (Expand Search)
petruuv » peteruuv (Expand Search), petruuuv (Expand Search), petrouuv (Expand Search)
petruuuv » peteruuuv (Expand Search), petruuuuv (Expand Search), petrouuuv (Expand Search)
petriv » peteriv (Expand Search), petruiv (Expand Search), petroiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrouo » peterouo (Expand Search), petruouo (Expand Search), petroouo (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 (((petruuv OR (petruuv OR petruuuv)) OR petriv) OR (((petri OR petrouo) OR peri) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruuv OR (petruuv OR petruuuv)) OR petriv) OR (((petri OR petrouo) OR peri) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruuv OR (petruuv OR petruuuv)) OR petriv) OR (((petri OR petrouo) OR peri) OR petr)) o.s.*.