Perhaps you should try some spelling variations:
petruoov » petrov (Expand Search), peteruoov (Expand Search), petruuoov (Expand Search), petrouoov (Expand Search)
peteroiv » petrov (Expand Search), peterdi (Expand Search)
petrooiv » petrov (Expand Search), peterooiv (Expand Search), petruooiv (Expand Search), petroooiv (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petruoi » peteruoi (Expand Search), petruuoi (Expand Search), petrouoi (Expand Search)
petroui » peteroui (Expand Search), petruoui (Expand Search), petrooui (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 ((petruoov OR (peteroiv OR petrooiv)) OR (((petri OR petruoi) OR petroui) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruoov OR (peteroiv OR petrooiv)) OR (((petri OR petruoi) OR petroui) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruoov OR (peteroiv OR petrooiv)) OR (((petri OR petruoi) OR petroui) OR petr)) o.s.*.