Perhaps you should try some spelling variations:
petroiiv » petrov (Expand Search), peteroiiv (Expand Search), petruoiiv (Expand Search), petrooiiv (Expand Search)
peru » petru (Expand Search), per (Expand Search)
petruv » peteruv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
petroiv » peteroiv (Expand Search), petruoiv (Expand Search), petrooiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petruuuo » peteruuuo (Expand Search), petruuuuo (Expand Search), petrouuuo (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 ((petruv OR (petroiv OR petroiiv)) OR (((petri OR peru) OR petruuuo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR (petroiv OR petroiiv)) OR (((petri OR peru) OR petruuuo) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruv OR (petroiv OR petroiiv)) OR (((petri OR peru) OR petruuuo) OR petr)) o.s.*.