Perhaps you should try some spelling variations:
petruov » peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petriuuov » peteriuuov (Expand Search), petruiuuov (Expand Search), petroiuuov (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrui » peterui (Expand Search), petruui (Expand Search), petroui (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 (((petruov OR petriuuov) OR (peteriiov OR petriov)) OR ((petri OR petrui) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petruov OR petriuuov) OR (peteriiov OR petriov)) OR ((petri OR petrui) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petruov OR petriuuov) OR (peteriiov OR petriov)) OR ((petri OR petrui) OR petr)) o.s.*.