Perhaps you should try some spelling variations:
petruv » peteruv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
petruov » peteruov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petriuo » peteriuo (Expand Search), petruiuo (Expand Search), petroiuo (Expand Search)
petrooiuo » peterooiuo (Expand Search), petruooiuo (Expand Search), petroooiuo (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 petruov) OR ((petri OR (peteruuo OR (petriuo OR petrooiuo))) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR petruov) OR ((petri OR (peteruuo OR (petriuo OR petrooiuo))) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruv OR petruov) OR ((petri OR (peteruuo OR (petriuo OR petrooiuo))) OR petr)) o.s.*.