Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petroov » petrov (Expand Search), peteroov (Expand Search), petrioov (Expand Search), petruoov (Expand Search)
petrui » petri (Expand Search), petru (Expand Search), peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petriouiov » peteriouiov (Expand Search), petriiouiov (Expand Search), petruiouiov (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 (petriov OR petriouiov)) OR ((petroov OR petrui) OR (petr OR petrui))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruov OR (petriov OR petriouiov)) OR ((petroov OR petrui) OR (petr OR petrui))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruov OR (petriov OR petriouiov)) OR ((petroov OR petrui) OR (petr OR petrui))) o.s.*.