Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petrui » petri (Expand Search), petru (Expand Search), petriui (Expand Search), petruui (Expand Search), petroui (Expand Search)
petriuo » petriiuo (Expand Search), petruiuo (Expand Search), petroiuo (Expand Search)
petruouuo » petriuouuo (Expand Search), petruuouuo (Expand Search), petrououuo (Expand Search)
petriuuo » petriiuuo (Expand Search), petruiuuo (Expand Search), petroiuuo (Expand Search)
petr » petri (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 petrui) OR ((petriuo OR (petruouuo OR petriuuo)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR petrui) OR ((petriuo OR (petruouuo OR petriuuo)) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR petrui) OR ((petriuo OR (petruouuo OR petriuuo)) OR (petr OR peter))) o.s.*.