Perhaps you should try some spelling variations:
petriuov » petrov (Expand Search), peteriuov (Expand Search), petriiuov (Expand Search), petruiuov (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petrioi » peterioi (Expand Search), petriioi (Expand Search), petruioi (Expand Search)
petriuo » peteriuo (Expand Search), petriiuo (Expand Search), petruiuo (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 (((petriov OR petriuov) OR petriuov) OR (((petroi OR petrioi) OR petriuo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petriuov) OR petriuov) OR (((petroi OR petrioi) OR petriuo) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petriuov) OR petriuov) OR (((petroi OR petrioi) OR petriuo) OR petr)) o.s.*.